Opal is a well-known example of a mineral whose color is caused by a physical phenomenon called “diffraction.” Other phenomena include iridescence, a rainbow effect seen in iris quartz and pearls; chatoyancy, which we see in cat’s-eye stones and some malachite; asterism, which is displayed in star stones; aventurescence, as seen in aventurine quartz and sunstones; adularescence, seen in moonstone; and play of color, or the alexandrite effect, seen in the alexandrite variety of chrysoberyl and some garnets. In every one of these groups, the cause of the color is related to some internal physical structure and not a metallic impurity or element in the mineral’s structure.

Opal Color

For centuries, people tried to explain the play of color seen in many opals. Finally, in the 1960s, we developed equipment that could actually see the internal structure of opal. It revealed a very orderly arrangement of submicroscopic spherules of silica. These spherules and the spaces between them acted as a diffraction grating, spreading light into its various colors. The sizes of these spherules and the angle the light struck them, coupled with the viewer’s angle, determined which color wavelengths were canceled and which ones were reflected. Diffraction of light results in opal’s play of color.

Labradorite Color

A more common mineral that gets its play of color from diffraction is the feldspar mineral labradorite. This mineral can develop in huge formations, resulting in outcrops that give off flashes of color.

Labradorite crystallizes in thin wafers in parallel layers that repeat to form a diffraction grating. This has the effect of separating light into its colors, giving labradorite a play of color that depends, in part, on the angle of the source of light. The thickness of each crystal and each cluster of crystals in their parallel layers also affect which color is seen. Labradorite can flash bronze, blue, green, and in some cases, red or violet in an overall groundmass of gray to blue. It is thought the gray color of the groundmass is due to the scattering of light by the internal structure.

Play of Color

Another attractive feldspar mineral is adularia. Like labradorite, it develops as thin crystals that line up in parallel arrangement and act as a diffraction grating. But adularia does not show a play of color. The twinned arrangement of the crystals simply scatters light. While it can also be shades of gray, pink, peach, green and brown, it is best known for a bluish-white color that is reminiscent of the moon.

Properly cut adularia gives off a cloudy sheen that seems to float throughout the polished stone. We give this lovely form of adularia the name “moonstone.”

Why does adularia have little color, while labradorite is a riot of color? Minerals color variations are because of minor variations in the refractive index of the labradorite crystals involved. In adularia, the refractive indices of the crystals are virtually the same.

Iridescence

Iridescence is described as a play of changing colors on a surface of a mineral. A prime example is the look of oil spread over the surface of water. The oil particles have a different refractive index than the water, and this physical difference results in a play of color.

The most common example of this phenomenon is called “peacock ore”, which is actually the mineral bornite (copper sulfide). A freshly broken surface of bornite quickly oxidizes, forming a thin oxide mineral layer whose refractive index differs from bornite’s and creates a play of color. More subdued examples of this iridescence are seen on some crystal surfaces of pyrite, cuprite, chalcopyrite and hematite.

Pearl Iridescence

Iridescence is what gives pearls their soft, moonlike luster, called “orient.” Pearls are made up of layer upon layer of microscopic crystals of hexagonal aragonite. The refractive indexes of these layers are the same. Colored and black pearls result from inclusions that get into the pearl’s structure.

Mother of Pearl’s lovely shimmer, or glow, comes from the interior lining of shells, which is made up of two different substances: the calcium carbonate mineral aragonite, which forms microscopic hexagonal crystals, and conchiolin, a fibrous protein that forms in layers in parallel arrangement. The parallel fibers of the conchiolin are the key to creating the iridescence we see in mother of pearl, also called “nacre.”

Chatoyancy

When the fibers of a mineral develop in a parallel arrangement, they impart a silky shimmer or glow of light, called chatoyancy, that can be very appealing. You can expect to see this shimmer in a range of minerals. Asbestos is a very common example. When the asbestos is invaded by silica, it can form what we normally call tiger’s-eye, which is a very useful chatoyant gemstone with a silky luster. The invading silica negates the hazard we normally associate with asbestos.

Iridescence Within Stain Spar

One variety of gypsum, called stain spar, also shows iridescence, or glimmer of light. The mineral looks like silk cloth, whose fibers are also arranged in a tightly woven, parallel structure. Another example of iridescence is seen in some malachite. This copper carbonate usually crystallizes in tightly packed needles, which grow in slightly diverging radiating masses. When freshly broken, these near-parallel fibers give off a shimmering green color.

Asterism is seen in minerals like diopside, gem corundum, some moonstones, and several others. In these species, included fibrous crystals of the mineral rutile, in an intersecting arrangement, reflect light in a six-rayed star pattern. This physical phenomenon is what creates rare star sapphires and rubies, which are very valuable varieties.

Cat’s-eye gems exhibit chatoyancy, as well as a single, bright, linear reflection from tightly packed parallel fibers of a second mineral. Lapidaries give these gemstones a slight to strong dome and orient them so that the included mineral, often rutile or tourmaline, runs straight across the curved surface to form a single bright line, much like the vertical iris in a cat’s eye. It is important to know that these included needle crystals are all oriented along just one of the several growth axes of the hexagonal corundum stone.

Hexagonal Minerals

Hexagonal minerals like ruby and sapphire develop along four axes: one vertical “C” axis, from which three axes develop at right angles to the “C” axis, 60º from each other. For a star gem to form, the included mineral orients along the two arms of each horizontal axis to create a six-rayed star.

Chatoyancy is also seen in the cubic mineral gem garnet. The difference is that garnets form in the cubic system so the “star” forms from needle crystals that have oriented along the two horizontal axes that make up the cube form. Only two axes extend away from the single vertical axis, so the four arms of these axes with their parallel, included needles can orient to form a four-rayed star.

Understanding Aventurescence

Aventurescence is another physical phenomenon that involves inclusions. In this case, the inclusions are usually large enough to be visible and are scattered throughout the crystal mass, rather than oriented in a particular alignment. These scattered inclusions act as reflectors that scatter the light entering the host mineral.

An intriguing example of this is the manmade material called “goldstone”, which is glass with copper inclusions that give the glass a bright reddish-gold color.

Aventurescence is named for a quartz variety called aventurine, which is a lovely green color thanks to included chrome mica. These tiny, green flakes, or spangles, are scattered throughout the quartz, giving it a diffused green color of varying intensity that is very attractive.

The most attractive gem that falls into this category is the feldspar variety sunstone. This very lovely gem is found in several places in Oregon and shows a fine orange to red color due to included copper diffused throughout the gem. In some examples, the copper orients within the feldspar so that wisps and feathers of color are prominent in the gem. Sunstone claims in Oregon are occasionally opened to collectors for a fee.

Alexandrite Effect

Finally, the alexandrite effect is seen in very few minerals whose color is based on the type of light source. The chrysoberyl variety alexandrite is the obvious example.

Alexandrite has a light absorption band that, in sunlight, can split light into two different transmission areas. Under sunlight and fluorescent light, some of the blue wavelengths are absorbed, so green becomes dominant. When seen under in incandescent light, alexandrite is red.

As you collect colorful minerals, be aware that not all of them owe their color to a trace element inclusion. This is another area of interest you can pursue as you enjoy our wonderful hobby.

This story about what gives minerals color appeared in Rock & Gem magazine. Click here to subscribe. Story by Bob Jones.

The post What Gives Minerals Color? first appeared on Rock & Gem Magazine.

January

Garnet has been the birthstone for January since the 15th century, at least. With a Mohs hardness of 6.5 to 7.5, it can be faceted into beautiful gemstones that wear well in jewelry. Since the term “garnet” actually refers to a group of nesosilicate gems, those born in this month can choose from a rainbow of colors.

The most common members are red almandine, an iron-aluminum silicate; red pyrope, a magnesium aluminum silicate; orange-yellow spessartine, a manganese aluminum silicate; the yellow or green varieties of andradite, a calcium-iron silicate; predominately green grossular, a calcium-aluminum silicate; and rare, bright-green uvarovite, a calcium chromium silicate.

February

From the 15th century to the present, amethyst has been the preferred birthstone for February. Amethyst belongs to a mineral family that can compete with garnet for diversity of color: quartz.

Pure quartz is colorless, as exemplified by Herkimer diamonds. The causes of amethyst’s shades of pale violet to rich purple are radiation and the inclusion of iron impurities and trace elements.

As a rule, amethyst crystals are short and stubby, and occur in large numbers, often filling a large vug a hollow petrified tree section, or lining the inside of a geode. Fine crystals that are large enough to produce a faceted gem of over 20 carats are rare.

March

The current choice of a birthstone for March is aquamarine. Aquamarine is a variety of beryl (Mohs 7.5-8). Its name was derived from the fact that the beautiful, transparent, blue-green coloration of the gem resembles that of seawater. It can be found in translucent to transparent crystals that form in the hexagonal system. The six-sided crystals are often striated lengthwise.

Aquamarine develops in metamorphic rocks and, more often, in pegmatites.

April

Before 1900, a person with an April birthday had two choices of birthstone: diamond or sapphire. During the 20th century, however, diamonds became the preferred stone.

Diamond, a mineral consisting of pure carbon, heads the list of all gemstones for its beauty and hardness. A 10 on the Mohs Scale of Hardness, it is resistant to scratching and is an ideal gem to set in rings. Its hardness results from the arrangement of its atoms in cubes.

All diamonds have slightly rounded faces, and they’re so smooth they feel greasy to the touch. They can be colorless and water clear to blue, pink, yellow, brown, green or black, and transparent or translucent. They shine with an adamantine luster when held to the light.

May

There were two choices for May birthstones for several hundred years: emerald and agate. The popularity of agate seems to have waned at the turn of the 20th century, so emerald is now the favorite. It’s the green member of the beryl family of gemstones. The color varies from bright green to pale green and, sometimes, darker shades of blue-green.

Fine emeralds have a velvety surface appearance and, in the better stones, an even distribution of color. One bad trait of emeralds is a tendency to have inclusions. It’s rare to find an emerald without some slight imperfection. This in no way deters from the beauty of this gemstone, though. It can also be one way of determining whether an emerald is a simulated gem or the real thing, as manmade stones have no imperfections.

June

The contemporary choices for June are pearl, moonstone and alexandrite. Of course, a pearl is the organic product of marine bivalves and not a mineral.

Moonstone is a variety of feldspar that shows adularescence, or schiller, an optical effect that produces a milky luster with a bluish tinge that appears to move across the stone when it is tilted. The phenomenon is named after the feldspar variety adularia.

Alexandrite is a color-change variety of chrysoberyl (beryllium aluminum oxide). This is a very rare and expensive gemstone. It has a hardness of 8.5, and its crystals are either tabular or prismatic. The distinction between alexandrite and chrysoberyl is simply color. A strange characteristic of alexandrite is that it is red, purple or violet when held under artificial light, but in daylight, it looks green.

July

Ruby is the standard birthstone for the month of July. It is a corundum (aluminum oxide) gem that gets its color from the presence of chromium in its structure. An exceptionally hard mineral, corundum illustrates a hardness of nine on the Mohs scale. “Pigeon-blood” red is the preferred color for rubies, though they also occur in lighter shades, including pink. All other colors of corundum are called sapphires.

Ruby exhibits all the desirable properties of a jewelry stone: beauty, durability, optical properties, and rarity. Some rubies display a star or asterism when fashioned into a cabochon. This effect is caused by the reflection of light from numerous inclusions of minute, needle-like crystals of rutile. Corundum crystallizes in the hexagonal system with a tabular-barrel-shaped habit.

August

Current birthstones for August are peridot, the gem-quality form of olivine and spinel. Olivine makes up a large portion of the earth’s mantle. Rocks containing olivine have been brought to the surface by volcanic action and actually blown out in the form of volcanic bombs. Masses of olivine have been found in meteorites, and the Apollo astronauts brought basaltic rocks back from the moon that contained olivine.

A popular jewelry stone, peridot has a hardness of 6.5-7 and can be transparent or translucent, with a vitreous luster. Its color shades from deep green to apple green, yellow-green or olive. It’s most often found in granular nodules, forming short, prismatic crystals in the orthorhombic system.

Spinel is the gem-quality member of the larger spinel group. Its hardness (Mohs 7.5-8.0) makes it ideal for jewelry use. Its spectrum of colors includes red, pink, purple, blue and lavender. In times past, red spinel was often mistaken for ruby. A notable example is the Black Prince’s Ruby, set in the royal crown of England.

September

The birthstone for September is sapphire. This term refers to any corundum (aluminum oxide) gem that has any color other than red (ruby). Sapphires may be colorless, blue, green, yellow, orange, brown, pink, purple, gray, black, or multicolor. At Mohs 9, its hardness is second only to that of a diamond.

Heat treatment is sometimes used to give natural blue sapphires a deeper, more pleasing color. Natural star sapphires, which display the optical phenomenon of asterism, are very rare.

October

Two options for October are opal and tourmaline. Opal is a magnificent gemstone with a play of color or “fire” in all colors of the spectrum. Spaces between the tiny spherules of silica that make up the gem diffract light into its spectral colors. Red, yellow, green and blue, in strong to pastel shades, flash from the stone when it is tilted.

Opal occurs in common and precious types. Common opal does not display any reflective fire. It may have a honey-yellow, brown, gray or colorless body color that is milky and opaque. Opal (Mohs 5-6) is not a very hard gemstone.

Tourmaline, a silicate of boron, has a complicated chemical composition, in which a number of elements, including calcium, iron, sodium and aluminum, may combine. It has a Mohs hardness of 7-7.5.

It belongs to the trigonal crystal system and its habit is hemimorphic (a crystal having two ends of an axes unlike in its planes).

Because of the coloration of the individual stones, tourmaline has several names, including schorl (black), rubellite (red), indicolite (blue), and dravite (brown). Tricolor crystals are common. The popular watermelon variety has an outer layer of green around a red core.

November

The current birthstones for November are topaz and citrine. People tend to think of topaz, a silicate mineral with aluminum and fluorine, as a yellow stone, but heat-treating and color-enhancing adaptations have made blue the predominant color on the market. It is an allochromatic mineral, which means its color is caused by internal defects in the crystal and has a Mohs hardness of eight.

Citrine is the golden member of the quartz family (silicon dioxide). Though quartz in its many forms is one of the most abundant minerals on earth, fine, gem-grade crystals are not that common. Citrine is affordable and, when faceted, rivals more expensive gemstones in beauty.

December

There are three birthstones for December: turquoise, blue zircon and tanzanite. Turquoise (hydrated copper aluminum phosphate) is an opaque, blue-to-green, massive gem material. It has a relatively low hardness of Mohs 5-6, so care must be taken with turquoise jewelry.

The rarest and most valuable variety is robin’s-egg blue with black “spiderweb” veins of limonite. Fake turquoise, consisting of dyed howlite or magnesite, is common. Buyer beware.

Zircon (zirconium silicate) can be blue, black, red, brown, green, yellow, smoky, or water-clear. It has an adamantine luster much like that of a diamond, and it is often misidentified as such.

Tanzanite, the blue/purple variety of zoisite (basic calcium aluminum silicate), is a recently introduced alternative for December. Tanzanite crystals in shades of yellow to brown, green, pink, gray or blue are often heat-treated to produce a gemstone that is a beautiful and permanent blue.

This story about what are birthstones by month previously appeared in Rock & Gem magazine. Click here to subscribe! Story by Kenneth H. Rohn.

The post What are the Birthstones by Month? first appeared on Rock & Gem Magazine.

Purchasing Pink Opal

If you’re looking to buy some of this material, you can find it on Glenn’s online store at: www.gemstonegeeks.com. It’s fairly easy to see what you are getting, as this comes from a horizontal seam, and the sides of each stone show its contents. Whether you are looking for larger areas of pure pink, swirling patterns, or brecciated variation, the pictures online will show you what you will be getting.

How to Slab Pink Opal

Slabbing this material is fairly easy, but with all opals including Ethiopian opal, it can be on the brittle side. If you plan on putting the rough in a larger saw gripped by a vice, I would suggest using a sintered continuous rim blade that is as thin as you can get it. Cutting with an aggressive thinner agate blade could cause fractures and massive unwanted chipping.

I suggest hand cutting on smaller trim saws, with a thin blade and water instead of oil. Once I have cut each slab, I normally put the slabs in a bucket of water until it’s time to cut cabs from it. Otherwise, it seems to dry out and fractures can develop.

The brecciated variation is definitely a fan favorite, and you shouldn’t have any concerns about its stability. The chalcedony running through it holds the opal together nicely.

When starting the cabbing process, bench tests each slab to ensure it will be stable. Opal almost always shows fractures. Although most are superficial, parts may break off where there is a fracture that is not even visible.

Trimming Preforms

For the most part, trimming out preforms is easy, but I did lose a couple to fractured pieces. This didn’t hinder me from cabbing them, but it did force me to alter the shape of the cab. I may not have gotten the desired shape I originally intended, but the stone itself chose a shape for me, which always turns out beautifully. There’s nothing wrong with redesigning a cab on the fly when you lose a piece or a chip from your original design; the colors and patterns of this material will look great no matter what.

Cabbing Pink Opal

To start cabbing pink opal, I would suggest a well-worn and broken-in 80-grit steel wheel to gently grind out your shape. Note, that the lighter the color, the softer it is. The dark rose is fairly hard, and the light pink to white is fairly soft, so if your 80-grit is aggressive, then start on a steel 220- or even a 60-grit soft resin wheel.

Once your shape is obtained, dome the top with a soft 60-grit wheel, with lots of added water. It’s important to turn the water up when cabbing pink opal so that you don’t add any extra heat from the friction of the wheels.

From here, I typically use a soft resin 140-grit, to remove all the remaining scratches. Once you finish getting your cab smoothed out, and scratches removed, move on to the 280- then to the 600-grit wheel. At this point, your cab should almost look finished, by the time you reach the 1200-grit wheel, your cab will most likely have a mirror polish and you will have a finished cab. If there are still some slightly dull spots, you can move up to a 3k or 8k soft resin wheel and lightly give it a final polish.

This story about pink opal previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Russ Kaniuth.

The post Pink Opal: What to Cut first appeared on Rock & Gem Magazine.

Putting the Pieces Together

One of those early buckaroos was Harry L. Wilson, who was born and raised in the Surprise Valley community of Fort Bidwell, and later worked cattle for an enormous, multi-state ranching operation before partnering with a couple of friends in 1925. “They bought homesteads that eventually became consolidated as the Virgin Valley Ranch,” says Julie Wilson, granddaughter and third generation to operate the Royal Peacock Mine.

The appeal of these pretty gems wasn’t the reason Harry L. Wilson purchased the nearby opal mine, which they later named the Royal Peacock, in 1944. It was all because of his wife, Mabel. He was all about the cattle and the horses, but she liked the “sparkle and bling.”

Beyond the beauty of the opals, this entire region is a world of its own. “The Virgin Valley is remote, but it was genuinely nestled in the boondocks in the 1950s. My grandfather lived on the ranch before Highway 140 connected Virgin Valley with Lakeview, about 100 miles to the west,” says Julie. “It was a time when Modoc County’s Surprise Valley towns of Cedarville, Fort Bidwell and Lake City were the nearest watering holes. There was no electricity until 1968 or telephone service until 1970. For years, my grandparents operated a cattle ranch and raised horses. It became surrounded by the Sheldon National Wildlife Refuge, which was created in 1931.”

Changing Times

When the refuge eventually expanded, cattle were no longer permitted on the land. This required the Wilsons to sell 1,600 acres of the ranch, which was the largest inholding in the area, to the Nature Conservancy. But they still had the mine and the remainder of the ranch.

Born in 1932, Julie’s father, Harry W. Wilson, naturally fit into the rhythm of this stunning landscape. He met his future wife, Joy Wimer, during their high school years in Cedarville. Julie comments that after they were married in 1953, her mother’s initial impression was, “I thought he brought me to the end of the world.’”

In the first few decades, there was some early small-scale commercial leasing and public fee digging. It wasn’t until 1973 that Julie’s parents shifted the focus of the mine, introducing more people to these beautiful gems. The couple is even responsible for petitioning the Nevada State Legislature to recognize the black opals from the Virgin Valley as the Nevada State Precious Gemstone. There is now an exhibit at the capitol building in Carson City.

“Over the years, millions of dollars of opals have been extracted from the family mine in Virgin Valley, which has more than 200 private claims,” Julie notes. To this day, the mine remains family-run with a keen focus on welcoming other families to this beautiful locale with the opportunity to find their own opals.

Growing Up at Royal Peacock

“All you find is yours to keep,” says Jake Anderson, Julie’s son who started working at the Royal Peacock in 2010 and has been a key figure in the mine’s operation since Julie’s father passed suddenly in 2016. Jake also runs their 500-acre alfalfa farm located a couple of hours from the mine.

“As a young boy growing up (Jake) would go stay with his grandparents, Harry and Joy, playing in the dirt at the mine with his brothers,” says Julie.

Spending so much of his childhood at the mine, Jake was privileged to be mentored by his grandfather who taught him how to read the layers of the hill, along with the “ins and outs” of operating a mine. “This allowed Jake to gain the knowledge of the past and the best ways to help people be successful in digging,” Julie notes One of Jake’s earliest significant discoveries was finding his first black opal when he was 14 years old. “I used to think fossilized wood was worth a million bucks,” he says, but one day when he and his brother were messing around, he broke a limb cast that was loaded with fire. Being immersed in the mine throughout his life, and understanding the satisfaction of finding these gemstones, allows Jake to help others experience the same thrill of discovering something truly special.

Through the tutelage of his grandfather, Jakes says he learned, “You’ll find (a treasure) when you least expect it.”

Continuing a Legacy

These words of wisdom turned out to be especially true for Jake when it came to meeting his wife, Cassie. In August 2020, Jake took a trip to the Spectrum Sunstone Mine in Plush, Oregon, and happened to meet a family from Washington. He immediately hit it off with Cassie as the couple worked together looking for sunstones, but ultimately, Jake and Cassie found a treasure in each other. Before Cassie’s family left for their next mining adventure, Jake gifted her with an opal from his family’s mine.

“The Royal Peacock was my family’s second stop,” says Cassie. She and her family traveled to the mine, leaving Jake to continue his effort looking for sunstones, but were pleasantly surprised when they woke up the next morning with Jake parked outside of their lodging. The running joke in the family is that Jake claims, even to this day, that his phone broke, but others think it was a plausible excuse.

Regardless of the phone functionality, Jake discovered his ideal mate. Cassie has gemstones in her blood.

“My parents got me started when I was seven,” she says when they visited Crystal Park in Montana looking for amethysts and crystals. “It’s incredible what the earth can create. I’m so blessed to have been able to become part of this family.” She’s equally smitten with the terrain in this remote country. “It’s an oasis out there, that’s for sure. It’s absolutely beautiful.”

Continuing a Legacy

From this serendipitous meeting, the two married and continued the family legacy with the birth of their son, Sterling HB Anderson, the fifth generation of the Royal Peacock Opal Mine. “It just means the world to me.

I am still in shock,” says Jake.

Julie admits she was wondering whether Jake would ever meet anyone and continue the legacy of the family mining business.

“When he met Cassie, it changed our lives forever,” she says.

With a focus on the future, the entire family strives to make the mine viable for generations to come. Julie always has an eye on annual improvements to the mine and the campgrounds.

“Every time she says, ‘Here’s what I was thinking” (almost daily) to the crew, we all know we are in for a new project,” jokes Cassie. As Julie looks to the future, her intent is to hand over the torch to Jake and Cassie, allowing her to make time for things she has always wanted to do, but never had the time.

A Place for Nature

Besides a premiere opal mine, their family’s legacy is a place of beauty and serenity. Jake says if folks like wide open spaces and the ability to see for miles upon miles, this is the place to be. There are also exceptional bird watching opportunities, trails for ATV adventures and hiking routes throughout the area which are favorites for those searching for a time to unwind. However, it is important to note that there are many active mining claims, which make it important to not trespass.

Julie also notes that they are blessed with rare dark skies for those who wish to experience the stars as few can anymore. With less than 80 percent of Americans able to see the Milky Way at their homes, looking up at the stars without light pollution is something few people forget. This is just another special aspect of this place they call home.

With their roots sunk deeply in the opal-rich earth, Julie, Jake and Cassie, along with their hardworking crew, look forward to the future. They are proof that treasures come in many forms, and for this family, what is most precious is being together in the place they were meant to be.

This sponsored story about the Royal Peacock Opal Mine previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Amy Grisak.

The post Exploring the Royal Peacock Opal Mine first appeared on Rock & Gem Magazine.

I see lots of new materials being introduced into the lapidary world. There have always been a large number of “purists” who do not like to work with anything that is not a natural stone, but many like myself feel that trying something new can be fun, adventurous and challenging.

Intrigued by Synthetic Opal

After reading through Roy’s website and admiring all the various pictures, I was definitely intrigued enough to try this material.

I purchased the red and white variations to try first and was just amazed when the material arrived. Whether outdoors in natural sunlight or indoors, the play of color in this material was just outstanding!

To begin with, I cut the blocks I received from top to bottom into slabs about 6 mm thick. Usually, when cutting smaller items, I use a 10-inch trim saw, running just with water. Since Aurora Opal is a resin-based material, I don’t see any issues cutting it with either water or oil in the saw.

When you have cut your slabs and preform shapes and are ready to start the cabbing process, remember that this material is only four on the Mohs Scale of Hardness, so you definitely want to start on a less coarse-grit wheel; I suggest the 220 grit wheel.

Committed to the Drying Process

With all resin-based materials, it’s important to dry off the cab at every interval of the process to check for any deep scratches from the prior stage. Micro swirl marks are quite common with synthetic materials but don’t be too alarmed in the earlier stages, as they will work themselves out as you go.

I made several cabs from this material, experimenting with different dome heights to see if there was any difference in color play, and in my opinion, higher domes catch the light from all angles, making the cab more eye-catching when set into a finished jewelry piece.

You can also experiment with the color swirl angles. They seem to run more horizontally in the tray, so when you get your blocks cut down, try orientating some horizontally and some vertically for variety.

Cabbing Aurora Opal

The cabbing process is quite simple, starting with 220 grit and ending with 14000 grit. Higher-grit wheels will definitely give you a glossier shine, but they are not a necessity. Once I finished on the 50000 grit wheel, the cabs were perfectly ready to be set into jewelry.

I don’t think any further polishing compounds are necessary, but if I were to attempt to go a step farther, I would use white rouge lightly to finish the polishing. Be extremely careful not to heat the stone up while attempting to polish though—this is a resin, and will melt if heated up too much. Then it’s back to the drawing board!

This What to Cut column about aurora opal previously appeared in Rock & Gem magazine. Click here to subscribe! Story and photos by Russ Kaniuth.

The post What to Cut: Aurora Opal first appeared on Rock & Gem Magazine.

Iridescent Opal

The gemstone that is synonymous with eye-catching iridescence is opal, the national gemstone of Australia. Opal is prized for its kaleidoscopic displays of fiery iridescence. It also consists of packed layers of nanoscale silica spheres. Depending upon their arrangement, these layers act as thin films and diffraction gratings to create the distinctive “patchwork” of structural colors known as opalescence.

Sunstone & Moonstone

Two other gemstones that occasionally exhibit iridescence are sunstone and moonstone, both of which are translucent varieties of feldspar minerals. In sunstone, a bright, golden glitter enlivens the stone’s brownish-red body color. This non-iridescent glitter, known as aventurescence, is caused by light reflecting from included microparticles of hematite and goethite. When these particles act as diffraction gratings, the stones exhibit a greenish iridescence.

Moonstone is named for its soft, moon-like, silvery-to-bluish-white sheen. This non-iridescent effect, called adularescence, is due to microscopic inclusions or lamellar twinning planes that diffuse light. These inclusions and planes can sometimes cause thin-film or diffraction-grating interference that creates a delicate blue iridescence. Less common is “rainbow moonstone” with its array of pale cyan, green, and gold structural colors.

Iridescent Quartz

Iridescence also appears in certain forms of quartz. Rock crystal from a locality in India’s Deccan Traps has an intense iridescence, but only on specific crystal faces. Scanning electron microscopy reveals that these faces’ surfaces consist of the periodic ridges and grooves of repetitive twinning. These function as diffraction gratings to create the bright iridescence of “rainbow quartz,” fine specimens sold for thousands of dollars.

Surface coatings of particulate goethite and hematite can produce surface thin-film iridescence in rock crystal, while the interfaces of twinning planes and fracture surfaces can cause internal diffraction-grating iridescence. In botryoidal forms of translucent fire agate, a play of green structural colors sometimes accents the stone’s brownish-red base color, an iridescence caused by coatings of particulate goethite on internal growth-layer interfaces.

Iris Agate

Iris agate exhibits an unusual iridescence. In reflected light, finely banded, semitransparent iris agate has a drab, gray body color. But when backlighted, thin slices cut perpendicular to the banding produce a circular rainbow of structural colors, called an “iris,” due to the diffraction-grating effect of microscopic growth layers.

The brilliant iridescence on botryoidal goethite specimens is due to microscopic surface layers of “turgite,” a mix of goethite and hematite that causes thin-film interference. Turgite films also create iridescence on fracture surfaces of flint and other types of microcrystalline quartz.

Rainbow Obsidian

Aptly named rainbow obsidian displays both internal and surface iridescence. Obsidian, a volcanic glass, typically has inclusions of mineral particles or gas bubbles that act as diffraction gratings to produce internal iridescence; weathering produces thin-film, surface iridescence.

Surface coatings and internal twinning planes occasionally create iridescence in such minerals as calcite [calcium carbonate, CaCO3], fluorite [calcium fluoride, CaF2], and several garnet-group members, notably andradite [calcium iron silicate, Ca3Fe2Si3O12].

Satin Spar

Satin spar, the fibrous variety of gypsum [hydrous calcium sulfate, CaSO4·2H2O], can exhibit both chatoyancy and iridescence. Satin spar’s densely packed, longitudinal fibers scatter light to create chatoyancy, a soft, glowing, white band that shifts as the viewing angle changes. When properly spaced, these fibers become diffraction gratings that cast a soft, iridescent cyan.

Iridescent Shells

Abalone shells and certain other seashells are also often iridescent. These shells’ nacre linings consist of tightly packed layers of hexagonal platelets of aragonite, the orthorhombic polymorph of calcium carbonate. These act as diffraction gratings that impart a soft, pink-and-green iridescence to the shells’ inner surfaces.

Fossilized shells of nautilus-like ammonites, notably those from the Bearpaw Shale formation in Alberta, Canada, show intense magenta-and-green structural colors due to the diffraction-grating effect of their aragonite layers.

Iridescent fossilized ammonites are sold commercially as “ammolite” and worn as pendants. Most pearls have uniform, non-iridescent, white, or cream body colors. But when nacre layers cause diffraction-grating interference, pearls can appear multicolored with an overtone or “orient” of soft, pink-and-green iridescence.

Synthetic Iridescence

Certain human-made materials are also iridescent. Most ancient glass, and even modern glass that has been buried for a few decades, become iridescent when weathering separates its surface into thin films.

Mass production of synthetic, iridescent materials began in the early 19th century when European ceramic artists began mixing silver and copper oxides into glazes for fine china. High-temperature firing reduced these oxides to metal microparticles that acted as diffraction gratings. In 1894, the American jewelry and decorative-art designer Louis Comfort Tiffany patented a similar process to manufacture his famous line of iridescent “Favrile” glass.

Synthetic Bismuth

The intensely iridescent, synthetic bismuth crystals are often seen in rock shops and at gem-and-mineral shows are made by cooling molten bismuth slowly so that it solidifies into “hopper”-shaped crystals.

The solidifying bismuth’s surface reacts with atmospheric oxygen to produce thin, bismuth-oxide coatings and resulting in thin-film interference. Even slag, the waste produce of metal smelting, can be iridescent when concentric surface layers of silica produce thin-film interference. Iridescent smelter slag is occasionally fashioned into jewelry.

CDs and DVDs

The playing surfaces of polycarbonate-plastic CDs and DVDs are another example of human-made iridescence. These disks are engraved with thousands of nanoscale grooves and ridges arranged in spiral tracks and coated with a bright, metallic finish. These highly reflective, diffraction-grating surfaces create a wide range of iridescent colors. Material scientists have recently developed lacquers and paints that impart iridescence to such products as cell phone cases, fingernail polish, and automotive finishes.

Artificial Iridescence

But not all structural colors are iridescent. One example is the kaleidoscopic “patchwork” patterns seen in photomicrographs of thin sections of rock. These structural-color images of a rock’s microcrystals are caused by cross-polarized light reflecting from, or passing through, birefringent mineral crystals. Because these structural colors are mineral-specific, they help to identify the rock’s mineral components.

Artificial iridescence can be readily imparted to non-iridescent mineral specimens, and iridescence’s intensity can be enhanced on those that are naturally iridescent. The colorful, iridescent “peacock ore” sold in rock shops as “bornite” is usually golden chalcopyrite that has been oxidized by acids or rust-removal compounds to produce an artificial iridescence. Bleach can also induce an attractive iridescence to disk-shaped pyrite “suns.”

Additionally, vapor-deposition processes can inexpensively emplace metal-oxide coatings that, through thin-film interference, transform common rock crystal into artificial “rainbow” quartz.

This story about iridescent minerals is part of a two-part series that previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Steve Voynick.

The post Iridescent Rocks: The Rainbow of the Mineral World first appeared on Rock & Gem Magazine.

I developed an interest in rockhounding a few years ago. I was watching a television show about hunting opals in Australia. I saw some pretty nice opals found under rugged conditions. I fully understood that what was on television was only the best and most exciting parts and that they didn’t show all the work and disappointment. However, the little seed was planted in my mind!

I mentioned my interest to my long-time friend Alison Betts, an Olathe Gem and Mineral Society member. The club is located in Olathe, Kansas. Alison also started watching the show. We agreed it would be an adventure, but too long and too expensive of a trip, to go to Australia. Alison started making inquiries about where to find black opal in the United States. She found that the best place to find black opals in the U.S. is in the northwest corner of Nevada. After completing extensive research on the internet and making multiple phone calls, we decided the place for us to go was the Royal Peacock Opal Mine in Virgin Valley, outside of Denio, Nevada.

A month later, I joined the Olathe Gem and Mineral Society. Then, armed with projected cost, Alison and I presented our rockhounding road-trip itinerary to the Society. We extended an open invitation to the members to join us in having an adventure at the Royal Peacock Opal Mine. While several people were interested, we had two members commit to the adventure, Barbara Crompton and Mike Purduski. With the addition of these two members, our adventure was set! With our group’s average age being over 65, the excursion became “A Senior Adventure.”

HITTING THE ROCKHOUNDING ROAD

We rented a van in Kansas City and loaded up the night before our departure. (Note: Rental vans from most rental companies do not include a spare tire and jack. This fact was not explained to us upon picking up the van).

On September 1, 2020, at 7:30 a.m., we set out for “A Senior Adventure” of 1,550 miles each way. With a projected drive time of 23 hours, covered by four drivers, we decided to drive straight through to the Royal Peacock Opal Mine.

We arrived the next day, a couple of hours before check-in, and decided to drive around and explore the area. Then it happened!

We were almost back to the Royal Peacock campground when the van’s low-tire indicator showed on the dashboard. We made it back to the campground and checked-in and checked all of the tires — they looked good. Then Craig, our guide at Royal Peacock, took us on a tour of the mine, giving us instructions on how to prospect the wall. While there, one of the miners showed us a very nice black opal with “fire” play-of-color that she had found that morning. That really got us pumped up!

Although it was explained to us several times that it was a hit-or-miss situation, we are ready and excited for three days of prospecting!

We got back to the campground, and the right front tire of the van was flat. We were in the middle of nowhere with no jack and spare, and 158 miles from a major city. Even so, at that moment we wanted to appreciate our surroundings, so we did.

ACCOMODATION APPRECIATION

The Royal Peacock Opal Mine and Campground includes two cabins, one with two beds and one with three beds. The cabins are equipped with a gas grill and firepit. There are multiple 30 amp and 50 amp sites with water hook up and several primitive sites. The sites I liked most are located under a row of Russian olive trees. The shower houses and bathroom areas are modern and very clean! The rock/gift shop was very quaint, offering souvenirs with a large selection of jewelry, rocks, and gems available. The office is where visitors can also pick up ice and ice cream bars on the honor system. Yes, it is that kind of easy-going place.

In addition to a laundry room, there are picnic tables scattered around the campground. It is a very picturesque and quiet facility with plenty of flora and wildlife. I found the staff very friendly and patient, always ready to help and to answer my rookie questions. Remember, being this is a very remote location, cell service and the internet are spotty.

After appreciating all of our host area’s wonderful amenities, we were back to dealing with the rental van situation. After cussing and discussing the situation on Wednesday morning, the rental company finally agreed to send a tow truck from Lake Tahoe to arrive at approximately 6 p.m. and take the van to the Reno airport for exchange. Alison, the primary car renter, and Barbara were to ride along to the airport in Reno, which was approximately 360 miles away. They had to stay overnight and drive the replacement van back the next day. The worst part was they missed out on two of our three days of opal prospecting due to the darn van.

ON TO PROSPECTING

On our first day of prospecting, Mike found some very nice opals, as well as some smaller opals. On my first day, I found some smaller opals but nothing to get excited about. The temperature became very warm, and there was no wind in the afternoon. We would prospect for an hour and then take a break in the truck. It provided great shade and air conditioning.

On the second day of prospecting, Mike found a few opals, but I found very little. Taking a break in the truck, we would open the doors and catch a welcome breeze. The breeze picked up in the afternoon, with a couple of small dust devils active above the wall of the prospecting area. Once, as I was leaving the truck to go back to prospecting, a larger dust devil came into the mining area, and I got caught in the middle of it. That was a unique experience for about 15 seconds. All I could do was close my eyes, put my head down, and hold on to my hard hat. Once it passed, everyone went back to prospecting.

Craig, our guide, helped the other prospectors and us a great deal. He put in a lot of work showing us the best techniques for prospecting and helping us identify the different rocks we were coming up with (false alarms) and the occasional opal. He is very patient and knowledgeable.

It was the end of the second day, a day where no one had found much, when with 15 minutes of prospecting time left, I uncovered a dime-sized opal in the wall. When I called Mike over to see it, we realized I had uncovered a large black opal. We were excited to say the least.

There was still some color within the wall, and I asked Mike to work it while I went and got Craig. With just 10 minutes of prospecting time left, Mike made two strikes around the color and out popped another piece of black opal, even larger than the first. We’ll call it beginner’s luck – but it sure was fun!

On our final day of prospecting, Alison and Barbara were back and able to join us in digging at the wall. One of the best parts of prospecting at Royal Peacock Opal Mine is that no climbing is required, as you can park a vehicle 50 feet from the mine and start digging. We felt spoiled being so close.

This may have been a “senior adventure,” but the ease and quality of the mining and accommodations make it a place for all ages. Our entire group recommends this as a MUST destination for rockhounds of all ages.

**An extra-special “thank you” to Julie Wilson, owner of Royal Peacock Opal Mine, for the loan of her landline in helping us get in touch with the van rental company and lending us her pick-up truck to get to and from the mine.

Editor’s Note: To learn more about the fascinating history of the family-run Royal Peacock Opal Mine, Inc., visit the Rock & Gem Digital Issues Library and download (for free) Issue 1 of “Illustrious Opals.”

All photos by Gary A. Monroe

Hide i

If you enjoyed what you’ve read here we invite you to consider signing up for the FREE Rock & Gem weekly newsletter. Learn more>>>

In addition, we invite you to consider subscribing to Rock & Gem magazine. The cost for a one-year U.S. subscription (12 issues) is $29.95. Learn more >>>

The post A Rookie Prospector’s Tale first appeared on Rock & Gem Magazine.

By Antoinette Rahn

Fulfilling a Childhood Dream and Aiding Others

Adam Sawicki, the owner of A&S Opals, LLC, first discovered the beauty, magic, and mystery of opal gemstones when he was just a child. Although that moment took place more than 30 years ago, the memory is forever etched in his mind and remains a source of inspiration.

“My love affair with opals began at five years old, sitting at the kitchen table watching a PBS program about Coober Pedy,” Sawicki said. “I promised myself then if I ever had a chance to go someday, I would.”

Someday turned out to be 2013, when he made his inaugural trip “Down Under.” That same year, he officially incorporated as A&S Opals, LLC, and he’s been back countless times, usually traveling to Australia two to three times a year. As Sawicki explained, he works closely with a select group of miners with whom he enjoys an excellent trusting and long-term relationship.

Dream Destination Turned Reality

“I love Australia and love spending time there,” he said. “I would go a lot more often if time allowed. I already knew I wanted to start my own business before I got to town (Coober Pedy), but I could not have anticipated how much (my) passion for the opal industry would be awakened until I was there. It was truly a life-changing experience in so many ways. That trip sent me down a path that lead to where I am today.”

Perhaps one of Sawicki’s most memorable opal trips was his extended stay in Lightning Ridge, Australia, during the early days of the COVID-19 pandemic in 2020. It wasn’t his original plan to stay as long as he did, but due to travel restrictions, if he had to be “stranded” somewhere, spending several months helping locals mine for opal is about as perfect as it can get for Sawicki.

All in all, things for Sawicki during the unusual year of 2020 are going fairly well, considering, he explained. In addition to a much shorter stay in Australia, he initially planned to sell at 10-12 shows, but many were canceled. However, even with the significant impact on his plans, the year has presented some new opportunities and positive outcomes.

“I have found that clients who I have met over the last several years during shows have been incredibly supportive and continued to place orders with me online as we had already developed good business relationships,” Sawicki said. “I have also noticed that during the COVID-19 lockdowns, many people have decided to follow their passions and entered the gemstone and jewelry world.”

Redefining Business

Sawicki, a supplier of both rough and finished opal and other Australian gemstones, explained how the change in the market makeup and purchase patterns have redefined his business this year.

“Although I’ve had a significant decrease in retail sales (due to the lack of shows and not having a brick-and-mortar retail space), I’ve seen a substantial uptick in my wholesale transactions due to all of the new small businesses starting up. I really enjoy helping the startup businesses, as there was little to no support available when I started in the opal industry.”

While Sawicki’s interest in opal dates back to his youth, and he formally went into business a little over seven years ago, it’s been two years since he made the leap into a full-time opal career. According to Sawicki, he made the change from a long-time career as a chef, which interestingly lends many skills to operating an opal business, he said.

“Previously, as a chef, I worked in open kitchen environments, which gave me a lot of face-to-face interaction with my clients. (The work) prepared me for the personal aspect of the business. I also routinely trained new restaurant staff; I now use those teaching skills to educate the next generation of opal cutters and jewelers,” he explained. “A career as a managing chef also prepared me for the business’s organizational, inventorying, and marketing (aspects). Making precise and repetitive motions with your hands, consistently and flawlessly, as a chef honed my dexterity and readied me for a career in the lapidary arts.”

Crossing Skill Sets

Another skill that applies to both culinary work and mining and selling opal is keeping an eye on changing trends and interests of the market and striving to serve those interests when possible. The selection of inventory available through A&S Opal, LLC, includes rough opal, opal rubs, cabochons, opal carvings, specimens and fossils, various other Australian gemstones, and finished jewelry.

“Each year, different color patterns become more or less popular. The same is true for different opal types, including black opal, semi-black opal, crystal opal, and boulder opal. Each of these types of opal is available in any selection of colors and a limitless array of unique patterns,” he said.

Sawicki went on to explain some of the influences to trends and the measures he takes to stay aware.

“As with anything nowadays, social media and television often create trends. When specific opals trend on social media platforms or are seen on shows like Outback Opal Hunters, (there is an increase in) demand for similar styles and types. I am always keeping my eyes and ears open. I ask my clients regularly what they would like to see, and I also often reach out to others in the opal industry to discuss what trends we have noticed.”

Increase In Opal Engagement

According to Sawicki, one of the current trends is an increase in the use of opals as the stone in engagement rings.

“The ethical nature of the Australian opal industry fulfills their need for social responsibility in their gemstone choice. The individuality of each stone also is a wonderful way of saying ‘you’re my one and only’ to their partner.”

Sawicki’s attention to detail, patient and mindful approach to serving customers, cultivating and strengthening business relationships, and his pure love for one of the most revered of gemstones are all part of one of the most valuable things he’s learned over the years, and most especially in 2020.

“I have learned that good business relationships and good friendships carry on through uncertain times. These relationships continue to be strong during even the most challenging times.”

All photos courtesy of A&S Opals, LLC.

For More Information

Visit: www.aandsopals.com
Email: aandsopals@gmail.com

The post Connecting With A&S Opals, LLC first appeared on Rock & Gem Magazine.

By Bruce McKay

The first fire opal I met from the Opal Queen Mine was brownish, had no play-of-color or any life to it, and didn’t impress me with its beauty. What did impress me was that this thing was as big as a football. The next time I saw material from this mine, it was some very beautiful rough and cut material; much of it reminded me of Mexican fire opal. The reddish-orange, glassy clear rough yielded lively, beautiful faceted stones and cabs. Although I had hoped to get to the mine and dig some of this material for myself, the mine was soon closed to public digging and remains so today.

This opal was first mined 100 years ago, and Tiffany’s of New York was among the early retailers that sold fire opal cut gems. The discovery of Mexican fire opal resulted in the material flooding the market, causing the value to drop and abandonment of the Opal Queen Mine. Today, Troy Newman and Michelle Shepherd of Outlaw Rocks in Lakeview, Oregon, own the mine and have generated renewed attention and appreciation for material from the Opal Queen.

Family Tradition

Both Troy and Michelle come from mining families going back generations. Troy’s father and uncles were gold miners, and his grandfather mined for gold and Mariposite. His great-grandfather was also a miner, making Troy a fourth-generation miner and his son a fifth-generation miner. Michelle’s mother was a gold miner in Northern California, and her grandfather and great-grandfather were Kentucky coal miners and moonshiners. While she certainly picked up the mining gene, I don’t think she has continued the moonshining tradition.

The home base for Outlaw Rocks LLC is Lakeview, a small town in eastern Oregon just north of the California border and a long way from almost anything. The locals claim that the community holds the distinction of being farther away from a freeway than any other town in the United States. Troy and Michelle mine opal from three different mines in the mountains west of Lakeview, mining opal in many different colors: red, red/orange, pink, white, blue, and brown.

The Opal Queen produces the reddish-orange opal, transparent and translucent varieties, and chocolate brown opaque to translucent opal. No play-of-color opal has yet been found at this mine. The miners cure larger pieces by putting the rough in a bucket in a cool dark area with consistent climatic conditions for up to a year before selling. This curing process helps prevent or reduce crazing or cracking of the stone after removal from the conditions it lived in for thousands or millions of years. The opal from this mine is marketed in the United States and Britain as American Fire Opal.

The Pink Lady Mine yields mostly opaque pink common opal in shades from light pink to red plus some opaque white. The opal from this mine needs no curing.

The Blue Maiden Mine is the most recent discovery by Outlaw Rocks, producing opaque blue common opal in a beautiful denim blue color. Troy and Michelle found this mine by old-fashioned sleuthing after hearing that blue opal, including a variety with play-of-color, was found in a creek in the nearby Fremont National Forest. Troy began to scour the hills, working up from where they found traces in the creek. He consistently searched for six years before he found a large tree that had fallen over. In the hole left by the tree root, he found the source of the blue opal he had been searching for so long to find. He quickly filed a claim and named it the Blue Maiden Mine.

All of the blue opal mined so far has come from this one hole, and all of it is opaque common opal with no play-of-color. The knowledge that play-of-color opal must be nearby has kept Troy and Michelle hopeful and digging.

First-Hand Adventures

Troy and Michelle invited me to visit their mines in the summer of 2019. I asked my friend Ken to come along, even though he has no particular interest in rocks but does enjoy a good adventure. We camped in the backyard of Troy and Michelle’s property near Lakeview, Oregon, which is located within an hour of the three mines. First, we went to the Pink Lady Mine. The mine is a V trench that cuts up the hillside a few hundred yards. It is surrounded by trees with a beautiful view over the Fremont National Forest.

We drove to the top of the trench and walked down to the most recent opal discovery. Using hand digging, we soon found some very nice Pink Lady opal, some lighter and some richer in color. The color in this area ranges from white to red, with most material appearing in the pink range. I did not uncover any white or red opals, just some pretty pink opal.

The next mine we went to was the historic Opal Queen. This mine sits on top of a sparsely treed hillside with an expansive view over a large ranch valley and the Fremont National Forest. We walked down the hillside from the mine over a rocky slope, and opal pieces were scattered everywhere. It is easy to see how people discovered this mine. The deposit is an open-pit, measuring about a quarter acre. At the bottom of one section of the pit, about 20 feet in depth, is a pond full of tadpoles. Thick seams of opal up to two inches wide could be seen filling the surrounding volcanic basalt cracks. The mining here is done with electric jackhammers, working around the opal to break it free from the basalt without fracturing the opal.

We jackhammered around exposed seams near the floor of the pit and on the face of a wall that had visible vugs of opal. We found some very nice red-orange opal with excellent transparency, plus some more translucent to opaque. I could also recover from the pit wall, a 15-pound piece, with color that ranges from chocolate to a translucent orange-brown. That chunk will be large enough for me to create a carving someday. My friend Ken found a nice piece of fire opal that I’ll cut and use to create a piece of jewelry for Ken’s wife, Anita.

Our next destination was the Blue Maiden Mine, where Ken and I climbed down into the hole beneath the storied tree root ball. We dug and dug and dug for maybe 15 minutes, coming up empty. The opal material in this mine comes in thundereggs, and we found plenty of empty eggs but no opal. While we were digging away down in the pit, Troy found a couple of nice pieces in the tailings pile.

The Blue Maiden Mine is on a gently sloping hillside that is mostly forested. A fire came through this part of the forest a few years ago, thinning out the trees quite a bit. Within a hundred yards of the pit are multiple pits where rockhounds have dug agate thundereggs. We picked up a couple of thundereggs, so we did not come off the hillside empty handed. The Blue Maiden holds much promise, and if they ever hit a pocket of blue play-of-color opal, it will be historic.

Opal Availability

You may have seen opal examples from this area, as chocolate opal from the Opal Queen Mine has been set into a line of jewelry and sold through QVC. Opal Queen Mine fire opal has been sold through Rio Grande, a jewelry-making supplier in the United States. Also, jewelry made using the fire opal from this area has been sold to Gemporia in England. Opal from the Pink Lady Mine has also been put into a jewelry collection and sold on television through ShopLC. And of course, Outlaw Rocks sells beads cut from the orange-red fire opal plus rough of all qualities from the mines at their site, www.outlawrocksllc.com.

Please note, none of the Outlaw Rocks-owned mines are open for public digging. However, you can enjoy a virtual dig excursion to the mines by visiting the Outlaw Rocks channel on YouTube.

For More Information

Visit: www.outlawrocksllc.com or www.facebook.com/royalpeacockopalmine
YouTube: Outlaw Rocks
Email: outlawrocksllc@gmail.com

The post Outlaw Rocks, LLC: Family-Style Oregon Mining first appeared on Rock & Gem Magazine.

Although most gemstones come from inorganic minerals, a class of “organic gems” consists of materials created by organisms (plants and animals) and used for lapidary purposes. Some organic gems have gained a notorious reputation, given that they are from endangered living creatures. These include ivory from elephant tusks and whale teeth. Additionally, rhino horn is often crafted into knife handles — popular in the Middle East. Certain species of endangered corals are also used in beaded necklaces and bracelets and sold in tropical climates.

Happily, some forms of organic gemstones endanger no living creatures. These come from critters that went extinct long before humans were around. One stunning example comes from ammonites. Ammonites were aquatic squid-like animals (cephalopods) that inhabited spiral-shaped shells and are tangentially related to today’s nautilus to which they bear a close but superficial resemblance. Along with non-avian dinosaurs, ammonites went extinct 66 million years ago when a huge asteroid smacked into Earth.

Like today’s nautilus, ammonites had mother-of-pearl shells. During fossilization involving heat and pressure, those other natural minerals have infilled mother-of-pearl nacre, reconstituted, and transformed into a material with an opal-like appearance called ammolite in the gemstone community. The Colored Stones Commission of the World Jewellery Confederation (CIBJO, www.cibjo.org) officially recognized ammolite as an organic gemstone in 1981.

The fossilization process transformed ammonite shell material into very thin, soft (Mohs 3.5 – 4) mica-like sheets. To be used as a lapidary material, ammolite often needs to be stabilized. One method involves gluing layers together with an infusion of a resin-like Opticon, epoxy, or acrylic or by crafting doublets or triplets with black backings and quartz caps, as with Spencer opal (see www.spenceropalmines.com/opal-triplets) to create sturdy cabochons. The best ammolite shimmers with vivid iridescent colors, much like black opal. A single piece may have red, orange, yellow, green, blue, and purple, all intermingling and shifting as you move the cab from side-to-side under a bright light. Stones on the blue end of the spectrum are considered the rarest and precious.

In the U.S., ammolite has been mined in Montana and Wyoming. But the most beautiful ammolite found on today’s market (sold under the trade name Korite) hails from Canada, especially the Bear Paw formation of southern Alberta on lands owned by the Blackfoot Native Americans. The tribe members prize the stone as “buffalo stone” because, according to legend, the stone saved the tribe one hard winter by bringing a huge herd of buffalo when the tribe was near starvation.

Thus, not only is this stone beautiful, some consider it downright magical!

Editor’s Note: Be sure to check out Rock & Gem’s FREE Illustrious Opals #3 digital issue, to enjoy articles about ammolite and opal triplets. Visit the Rock & Gem website to access: www.rockngem.com/illustrious-opals-library.

The post Ammolite — Beautiful and Magical first appeared on Rock & Gem Magazine.