Identifying the Risks of Radioactive Minerals

Understanding which parts of your collection may pose a risk is the first step. You might have just a few individual, radioactive mineral specimens. But some large rocks may also contain an amalgamation of multiple types of potentially radioactive minerals. In addition to these radioactive minerals, there are also daughter products that are created as the result of radioactive decay. Daughter products, such as radium, radon gas and uranium, are themselves radioactive.

According to Alysson Rowan, author of Here Be Dragons or The Care and Feeding of Radioactive Mineral Species, some radioactive minerals may even be hiding in plain sight. “A specimen that doesn’t look very good because it’s not well crystalized — somebody may cut that into a decorative stone and mount it for wearing,” Rowan says. “You can find these things on sale, and there’s no mention of the fact that it is radioactive.”

Based in Holsworthy, England, Rowan is also a former radiation safety worker with extensive training in geology. She continues, “There’s no mention that this is not something that you would want to wear, so, people buy these things and wear them in ignorance.”

Detection Equipment

Because uranium minerals tend to be very colorful, they’re among the most popular with collectors. “The other thing is that there are a lot of them that are fluorescent,” Rowan says. “With uranium minerals, you tend to get greens and yellows, but there are minerals that glow blue, and red, and I think there’s even one that’s now known to fluoresce purple.”

Incidentally, to test the radioactivity of your stash, you’ll want to purchase a handheld radiation detector. “If they’re going somewhere to collect uranium minerals or they expect to find uranium minerals, a handheld ‘Geiger counter’ is a must-have,” Rowan suggests. “Of course, they’re not all Geiger counters now. . . . A lot of them are scintillators which are a lot more sensitive and a lot more durable. They generally show how much radiation they’re detecting either on a meter or on an alphanumeric display.”

You can also find used Geiger counters for sale online. “A lot of people buy them second-hand on eBay,” she says. “The American Civil Defense monitors are very, very popular because there’s a lot of them about.”

Saléeite and autunite are two colorful — and radioactive — minerals. “In bright sunlight, you can see the fluorescence,” Rowan notes. Both are in the bright yellow-green range.

Just don’t get too attached to that autunite, as it will literally disintegrate. “Autunite is what’s known as a metamict,” Rowan explains. “It decays radioactively, and the radiation damages the crystal. Inside a few years, it’s just a pile of dust. . . . And, so, autunite will actually spread all over the place.”

Radiation Effects

Containing that radioactive spread is paramount because the negative effects of radiation on the body are cumulative. In other words? The radiation you absorb builds up over time. You can inadvertently expose yourself to radiation internally by absorbing contaminants through your skin. You can also inhale or ingest radioactive contaminants.

The acute effects of radiation exposure can range from erythema — akin to a deep tissue sunburn — to renal failure. “The uranyl minerals—that is uranium oxide as a radical—are toxic to your kidneys,” Rowan says. “So, that is what you’ve got when you pick up most fluorescent minerals. It’s uranyl phosphates, uranyl nitrates—they are highly toxic.”

Over the long term, exposure to some radioactive compounds can even result in bone cancer and leukemia. In her book, Rowan writes, “Inhaled uranous and thorium compounds, and to a lesser extent the uranyl compounds will result in both toxic and radiation damage to the lung. Long-term effects will include bronchitic and emphysema-like symptoms as well as a range of pulmonary and pleural cancers.”

Smoke Alarm

Keeping cigarettes, incense, and other smoky stuff away from radioactive specimens is especially important.

For safety’s sake, you should never eat or drink while handling radioactive minerals. Applying a quick smidge of lip balm’s another no-no. And smoking is right out, too.

“The thing about smoking is one thing that you do is that you handle the rock and you put your cigarette to your mouth and you’ve immediately got rock dust on your lips,” says Alysson Rowan, the author of Here Be Dragons or The Care and Feeding of Radioactive Mineral Species.

What’s more, let’s say some of your specimens contain uranium. As uranium goes through its multiple stages of decay, it eventually releases radioactive radon daughter products and radon gas. “The airborne activity from radon daughters and radon gas itself will attach themselves to smoke,” Rowan continues. “So, when you re-inhale smoke, you’re inhaling the radioactive contaminants in the atmosphere.”

In her work, Rowan writes, “It has been noted that the presence of blue smoke from cigarettes (the plume that rises from the burning tobacco) collects the radioactive radon daughter products more surely than any other means of concentration. This means that the spent smoke you breathe in a high radon concentration area is bringing those radioactive materials into your lungs in a form which tends to remain inside your body.” Such radiation exposure in the human body is cumulative. Rather than dissipate, the radiation exposure adds up. “The consensus of scientific opinion is that a given dose from radon is possibly 10 or 15 times as dangerous to a smoker as to a nonsmoker,” Rowan notes. To mitigate this risk, never smoke in areas where you keep radioactive specimens.

Minimizing Exposure

Although different minerals pose differing degrees of risk, if you are pregnant, you should avoid contact with radioactive minerals altogether. As for young children? “Before puberty, we are a lot more susceptible to radiation damage because of the rapid cell division,” Rowan says. “Children should not be around. . . radioactive minerals more than absolutely necessary for their study.”

There are several precautions you can take to minimize your overall radiation exposure and still appreciate the radioactive specimens in your collection. Besides the degree to which a mineral is radioactive, the amount of the mineral in question matters as well as the cumulative amount of time that you spend in direct contact with it.

“If you sit with a pound of uraninite using it as a paperweight on your desk, that is going to give you a problem eventually,” Rowan maintains. “If, on the other hand, you have that pound of uraninite and it’s in a lead-acrylic case, that reduces the dose rate and, therefore, it’s not quite the same problem.”

Display Do’s and Don’ts

“You also have to take into account how far you are from that specimen,” Rowan adds.

When you increase the distance between yourself and the specimen, you decrease your potential radiation dose. Adding shielding materials like lead, wood or glass can further reduce your radiation exposure.

“For the most part, you put [your collection] on display in a cabinet,” she says. “The idea is that you’re keeping dust off of your specimens, but you’re keeping dust from the specimens fixed.”

Regarding those uranium-rich minerals, keep in mind that uranium decays into radium which, in turn, will decay into radon gas. Because this heavy, radioactive gas can easily migrate, you should air out your uranium mineral display cases periodically. “I’ve done this with my own cabinet,” Rowan says. “You open the cabinet and stick your [radiation] meter in and the radiation count goes up. And, over about half an hour, the count rate goes right down, because the radon daughters in there only have a short half-life.”

Still, she cautions, “If you’re a serious uranium collector, then it’s probably a good idea to have vented cabinets—venting to the outside world.”

Also, never store or display uranium minerals in a basement. “Radon gas is an awful lot denser than air,” Rowan explains. “It’s a big atom and it will hang around for a couple of weeks.”

Handling How-To’s

If you do need to handle a radioactive mineral specimen, don’t dally. “If you’re working with it for too long, that’s all additional exposure,” Rowan says. “So, the amount of time that you’re in contact with the rock, you need to minimize it. And you need to make sure that you don’t spread contamination everywhere.”

To that end, she suggests wearing protective clothing and disposable gloves and protecting your work surface with a disposable covering. Washing carefully with soap and water is also key. “If you handle a radioactive rock, you’ve got radioactive rock dust on your fingers and you’ve got to wash it off,” Rowan says.

Finally, to prevent ingestion or inhalation of radioactive contaminants, never eat, drink or smoke when working with radioactive minerals, and, Rowan concludes, “Don’t be paranoid, but do take care.”

This story about radioactive minerals appeared in Rock & Gem magazine. Click here to subscribe. Story by Susan M. Brackney.

The post What are Radioactive Minerals? first appeared on Rock & Gem Magazine.

This stone, paradoxically celebrated for its beauty yet feared for its curse, is the Hope Diamond. The size of a walnut and a deep blue gem in color, it is the world’s best-known diamond. Over its 370-year-long, often murky history, it has become immersed in legend, stolen at least twice and cut four times. Its owners have included sultans, kings, bankers, jewelers, thieves, a popular stage performer, and a fabulously wealthy heiress.

Since 1958, the Hope Diamond has been a major attraction at the National Museum of Natural History (Smithsonian Institution) in Washington D.C., where it has been viewed by more than 100 million visitors and is currently valued at over $250 million.

Plucked From the Eye of an Idol

The Hope Diamond’s strange story began in 1653 when French gem merchant Jean-Baptiste Tavernier visited India’s Golconda Sultanate. There he purchased a crudely cut, triangular, flat, blue diamond of extraordinary size—115 carats. According to legend, this diamond, now known as the “Tavernier Diamond,” had been cursed since it previously had been plucked from the eye of a statue of a Hindu idol.

After returning to Europe in 1668, Tavernier sold the diamond to King Louis XIV of France, who ordered the stone recut. Tavernier wrote extensively about the gem before his death in Moscow the following year—when he was reportedly dismembered by a pack of wild dogs.

The “French Blue” and the Guillotine

The 1691 French crown jewel inventory describes the recut stone as “a very big, violet (the period term for “blue”) diamond, thick, cut with facets on both sides and in the shape of a heart with eight main faces.” It weighed 67.1 carats and was valued at the equivalent of $4 million in 2023 dollars. Formally known as the Blue Diamond of the Crown of France and popularly as the “French Blue,” this smaller stone, with its enhanced symmetry and additional pavilion facets, was substantially more brilliant than the original Tavernier Diamond. The French Blue was likely the first large diamond to be cut in a modern brilliant style.

Louis XIV had the blue diamond, along with a 117-carat red spinel and 195 smaller diamonds, set in an elaborate pendant that symbolized the Order of the Golden Fleece, a Catholic order of chivalry. Despite this prestigious setting, the idea that the French Blue was cursed gained credibility with the misfortunes of Louis XIV. Five of his legitimate children died in infancy. And the king himself died in agony of gangrene in 1715.

Setting the Stage

Ownership of the French Blue then passed to Louis XV, a monarch who enjoyed great popularity early in his reign—but his good fortune did not last. He engaged in costly wars that drained the French treasury, weakened royal authority, and set the stage for the French Revolution. Louis XV died a hated man in 1774.

The French Blue then became the property of King Louis XVI and his wife, the infamous Marie Antoinette, both of whom often wore the stone. But when the French Revolution erupted in 1789, the monarchy fell and, in September 1792, Louis was beheaded in a public execution. Marie Antoinette also died at the guillotine four months later.

A Convoluted Trail

During the French Revolution, the blue diamond, now widely believed to be cursed, was stolen from a royal warehouse and never seen again, at least not as the French Blue. The history of the stone then became uncertain. In 1812, just as the statute of limitations regarding the theft took effect, a 45-carat blue diamond appeared in the hands of London diamond merchant Daniel Eliason. Amid widespread accusations that this diamond was actually a cut-down version of the stolen French Blue, Eliason committed suicide.

In 1820, Britain’s King George IV acquired the diamond. Following his death in 1830, his bankrupt estate sold the stone to pay off debts. Attention then shifted to London banking heir Henry Philip Hope, who some suspected had secretly bought the diamond from French thieves in the early 1800s. Hope publicly listed the stone in his 1839 gem catalog—only to die just months later.

The Hope Diamond

The blue diamond remained with the Hope family for the next 57 years, the last owner being the American actress, playwright, and concert-hall singer May Yohé (Mary Augusta Yohé, Lady Francis Hope), whose writings and stage productions often called attention to the stone’s purported curse. The diamond was sold in 1896 to settle Yohé’s pressing debts. Many believed that the celebrated singer herself fell victim to the stone’s evil power: After enduring two disastrous marriages, she died in poverty in 1938.

The blue diamond, now known as the “Hope Diamond,” next passed through the hands of several gem merchants and jewelers, and two Ottoman sultans. The stone was then acquired by the prestigious Paris jewelry firm Cartier and director Pierre Cartier, a renowned wheeler-dealer in the gem world, who immediately began seeking a buyer and a quick profit.

On to America

The story of how the Hope Diamond came to the United States began in 1896 in the gold-mining camp of Ouray, Colorado, where prospector Thomas F. Walsh bought two abandoned claims for back taxes. This purchase turned out to be one of history’s greatest bargains, for the original claim owners had somehow overlooked a massive deposit of phenomenally rich gold ore.

In 1898, Walsh’s daughter Evalyn married Edward “Ned” Beale McLean, heir to The Washington Post newspaper fortune, and became an internationally known socialite with lavish tastes, especially for fine gems. When Thomas Walsh died in 1910, he left his fortune of $3 million ($90 million in 2023 dollars) to his 24-year-old daughter Evalyn Walsh McLean.

Pierre Cartier

Having previously sold fine gems to Evalyn, Pierre Cartier knew that the heiress, now in receipt of her fortune, was a prime candidate to buy the Hope Diamond. Pierre’s first attempt to sell her the stone failed. But he tried again, this time with the diamond set in a striking modern mount surrounded by a three-tiered circlet of dozens of smaller white diamonds.

Also astutely guessing that Evalyn would be fascinated by the stone’s purported curse, Pierre recounted—and likely embellished— its more disturbing details. In 1911, amid great publicity, Evalyn bought the Hope Diamond for $300,000 ($9 million in 2023 dollars). Enamored of the stone, the heiress frequently wore it at balls and parties, at times hanging it around the neck of her Great Dane or hiding it in the furniture and challenging her guests to “find the Hope.”

But in the end, Evalyn also seems to have paid dearly for owning the Hope Diamond: Her husband died in a mental hospital, her firstborn son was fatally struck by an automobile at age nine, and her 24-year-old daughter died of an overdose of sleeping pills.

Harry Winston & The Smithsonian

In 1947, New York City diamond merchant Harry Winston purchased the Hope Diamond from Evalyn Walsh McLean’s estate.

For nearly a decade, Winston displayed the stone on his popular “Court of Jewels” tour across North America, showing it at charity balls and on television shows. He ordered a minor recutting of the stone’s pavilion facets to further increase its brilliance—the fourth and last time that the Hope would be cut.

In the mid-1950s, mineralogist George Switzer, an associate curator at the National Museum of Natural History (Smithsonian), proposed establishing a national gem collection with the Hope Diamond as the centerpiece. Switzer asked Harry Winston to donate the stone to the Smithsonian. In 1958, Winston, intrigued by the idea of a national gem collection and perhaps even more so by a monumental tax write-off, agreed.

Winston sent the Hope Diamond from New York City to the Smithsonian in Washington, D.C., by registered, insured first-class mail. And what happened next convinced many that the Hope’s curse was still alive. Shortly after hand-delivering the stone, United States Post Office letter carrier James Todd was seriously injured in two back-to-back automobile accidents—before losing his house to a fire.

New Look at an Old Stone

For centuries, no conclusive proof existed that the Hope Diamond had been cut from the French Blue, or that the latter had been cut from the Tavernier Diamond. But in 2007, a Paris museum curator discovered a lead cast of the French Blue from which researchers prepared a three-dimensional, digital image. Comparisons with images of the Hope Diamond proved that the Hope had indeed been cut from the French Blue.

Researchers then computer-imaged the Tavernier Diamond based on Jean-Baptiste Tavernier’s detailed drawings from the late 1660s. Image comparisons confirmed that both the Hope Diamond and the French Blue had once been the Tavernier Diamond

A museum cataloging label also indicated that the lead cast of the French Blue dated to 1812 when the stone’s owner was a “Mr. Hoppe of London,” strongly suggesting that Henry Philip Hope had acquired the diamond not long after its theft during the French Revolution, then recut it to disguise its identity to avoid a French repossession lawsuit. After apparently passing the diamond on to Daniel Eliason, Hope seems to have reacquired the stone 25 years later shortly before his death.

“Proof” of the Curse?

Researchers have also learned that the Hope Diamond, when exposed to shortwave ultraviolet light, glows like a burning red ember. While many blue diamonds exhibit this same fluorescence, none match the Hope’s fiery intensity. Gemologists attribute this unusual fluorescence to traces of boron that also produce the Hope’s distinctive blue color. This boron interacts with other trace impurities, enabling electrons within the stone’s crystal lattice to absorb energy from ultraviolet light, and then release it as visible red light.

While gemologists agree that this fluorescence adds to Hope’s uniqueness, intrigue, and mystery, others attribute its eerie red glow to a demonic presence.

Despite the dark legends that still surround the Hope, this celebrated blue diamond has certainly not cursed the Smithsonian, which has benefited enormously through worldwide attention along with substantially increased gifting and visitor attendance.

This story about the Hope Diamond curse previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Steve Voynick.

The post The Hope Diamond Curse first appeared on Rock & Gem Magazine.

Fluorescent Minerals Defined

When collecting fluorecent rocks, it’s important to understand what gives minerals color and how light moves in waves and comes in different forms depending on the wavelength — infrared, visible, or ultraviolet. We are most familiar with visible light. Ultraviolet (UV) light moves in waves too short for our eyes to detect, but we can see its effects with certain minerals. What appears to be a drab gray rock in visible light may glow a vivid orange or green under UV light. Or a mineral of one bright color under visible light may appear a different color under UV. For instance, green fluorite may turn blue. Other minerals may stay the same color but appear much more intense, as with red ruby. In all cases, with UV light the minerals seem to glow from within, much like an electric neon sign glowing against a night sky.

What Causes Fluorescence?

Some minerals absorb ultraviolet light, which is invisible to us. But they then emit longer, visible light waves which we see as colors. At the atomic level, ultraviolet light causes electrons in some molecules to absorb extra energy and jump to a higher energy level. In falling back to a normal level, they give off that extra energy in the form of visible light. Thus the bright lights we see glowing in the dark.

Thank You, Sir George!

The first person to describe the phenomenon of rocks glowing in the dark under ultraviolet light was English scientist Sir George Stokes, 1st Baronet (1819-1903). Sir George was a physicist and mathematician at the University of Cambridge in England. In 1852, Sir George conducted experiments with fluorite under ultraviolet light. Because he was working with fluorite, he called the optical effect “fluorescence.” This, along with his many other scientific accomplishments, earned him the position of President of the Royal Society and Master of Pembroke College, Cambridge, along with service in the British House of Commons. He was a true polymath or a person with expertise spanning a wide range of subjects.

Short-Wave vs. Long-Wave

Ultraviolet light is usually divided into short-wave and long-wave. Most fluorescent minerals are sensitive to short-wave so most fluorescent mineral collections focus on such minerals. But some minerals will change color as you switch from short-wave to long-wave. It’s a good idea to have lamps that allow for both short-wave and long-wave illumination.

Does Every Mineral Fluoresce?

3,600 minerals have been identified, categorized, and named. Only 14 percent, or 500, fluoresce. To build a basic fluorescent mineral collection, seek minerals like calcite, opal, ruby, scheelite, willemite, celestite, hydrozincite, barite, scapolite, aragonite, and halite.

Learning More About Fluorescent Minerals

Good books for a fluorescent mineral collection include Manuel Robbins’ Fluorescence: Gems and Minerals under Ultraviolet Light, Stuart Schneider’s The World of Fluorescent Minerals and Schneider’s Collecting Fluorescent Minerals. You’ll also find many good websites and there’s even a Fluorescent Mineral Society (uvminerals.org) you can join.

If Working with Fluorescent Minerals, Beware

A warning! Don’t look directly into a fluorescent lamp. While long-wave ultraviolet light is relatively harmless, short-wave ultraviolet light can “sunburn” skin and eyes. Even though protective sunglasses can act as a shield, time spent with ultraviolet lights should be limited. Be safe, not sorry, while enjoying fluorescent minerals.

This story about florescent minerals appeared in Rock & Gem magazine. Click here to subscribe. Story by Jim Brace-Thompson.

The post Fluorescent Minerals 101 first appeared on Rock & Gem Magazine.

Minerals that are fluorescent under ultraviolet light are beautiful and fun, however, the great majority of minerals do not respond with color under ultraviolet light. Estimates vary from 10 to 15 percent of the known 5,000 minerals may respond. Including the rare earth elements, there are over 30 different common elements and ions that can cause fluorescence.

Self-Activating Minerals

Self-activating minerals use their own electrons to absorb ultraviolet energy giving their electrons the energy to shift away from the atom’s nucleus to the next higher energy level, or orbital. The remaining light energy is out of balance and reemitted and can be seen as a visible color. Ultraviolet energy is not visible so what you see is the lower electromagnetic energy level resulting from the action of the activator.

What Makes Minerals Fluorescent – Activators

The great majority of activators are atoms of certain metal elements which become part of the mineral’s chemistry by taking the place of atoms in the host mineral. For example, sodium chloride halite normally lacks color but if trace manganese atoms are present, they make the halite glow a lovely red under short wave ultraviolet radiation.

When the electrons in a responding mineral shift to a higher orbit they can’t stay there indefinitely. They are constantly shifting with blinding speed between their normal position and a higher orbital as the ultraviolet energy continues. Even though the electrons are shifting, the color we see is steady.

Known Activators

As we gain greater ability to pick apart a mineral, we are finding more activators at work and they are not all metal elements. Some are more complex ions.

Activators like uranyl oxide are regular participants in many radioactive minerals even with the trace manganese. These common activators have joined with some odd elements you would not think could trigger a color such as lead (Pb) in hydrozincite and sulfur (S) in sodalite, a variety of hackmanite from Canada.

What Makes Minerals Fluorescent – Rare Earth Elements

Rare earth elements are common activators. You see these elements listed at the bottom of the Periodic Table because they share many of the same chemical, physical, and mineralogical properties and a similar electron configuration of two valence electrons in an outer orbital.

Since rare earths often occur together in the same deposit, it is inevitable when an activator is present it can be any one of a suite of rare earths rather than just one element.

Two or more rare earth elements have been identified as causing fluorescence in some fluorite, strontianite, calcite, esperite, fluorapatite, powellite and scheelite. These last two are self-activating most often but can also respond to rare earths. The tungstate ion in scheelite is what responds to ultraviolet excitation, usually a brilliant blue under shortwave. In powellite, it is the manganese oxide ion that is the main activator causing a yellow response.

Why Activators Work

There is one other factor worth considering with activators. Why does an activator function only in certain minerals and not in all minerals? There are two reasons. The activator has to have a proper valence or number of electrons in its outer orbital, very often two. Its atoms also have to be close in size to the host atom that it replaces so it becomes part of the mineral’s chemistry and fits in the mineral’s lattice structure.

Manganese

Manganese is the most common activator. It is found in many of the minerals from the Franklin and Sterling Hill mining district in New Jersey causing the town of Franklin to be named the Fluorescent Mineral Capital of the World.

Manganese is a transition metal element which means its outer orbital can hold a varying number of electrons, in this case, two-three or four. They can be shared and become the agent in chemical bonding.

Usually, it is manganese valence two that ends up as a trace metal serving as an activator. In the mineral calcite, for example, it has a valence of two and can replace some calcium atoms with a similar valence in the mineral’s lattice structure.

Franklin-Sterling Hill calcite depends on manganese as its activator. The calcite can respond as a brilliant red. Studies have shown the optimum content of manganese activator in calcite at Franklin for a strong fluorescent response is about three percent. Too much of a good thing and the response is diminished, or not there at all.

The same valence two of manganese is also responsible for other fluorescent minerals from the Franklin mine. This is because these are zinc minerals and zinc has a valence of two. How about the size of atoms? Zinc atoms are close enough in size to manganese that they can replace some zinc.

Willemite easily accepts manganese atoms as an activator resulting in a bright fluorescent response but in this case green, not red.

Other minerals using manganese as an activator include pectolite, hardystonite, axinite, esperite, wollastonite and sphalerite. Some of these species also contain other trace metals like rare earth elements.

What Makes Minerals Fluorescent – Other Activators

Other activators are not simple elements. Some minerals may contain a trace of organic material like natural oil and will fluoresce. I recall collecting fluorite that included organics in the quarry at Clay Center, Ohio. The pale brown transparent fluorite cubes had a creamy or slightly bluish color depending on the type of ultraviolet lamp used.

Doubly terminated quartz crystals found in Herkimer, New York, may show fluorescence. “Herkimer Diamonds” developed in cavities created by organic stromatolites which existed millions of years ago. They died and left behind organic material which is picked up by the quartz as it forms. That’s what causes the fluorescence.

Recently Discovered Activators

We now know there is another group of activators not known decades ago consisting of two or three different elemental ions. Such things as carbon trioxide (CO 3 ) in calcite or topaz may cause a response. Much more important in topaz is the activator titanium oxide ion (Ti0 6). California’s official gemstone is benitoite a titanium mineral. It fluoresces a blue short wave thanks to the titanium oxide ion (TiO 3).

Certainly, the most frequently seen ion as an activator is uranyl ion (UO 2). It shows up in a host of radioactive minerals as well as other species.

Quenchers

While it seems that all radioactive minerals should fluoresce, they do not. Uraninite, the main uranium oxide mineral does not respond at all. A host of the popular radioactive minerals, like autunite, do fluoresce. But, the copper uranium mineral torbernite may not. This brings up the idea of quenchers, trace minerals that inhibit or prevent a fluorescent response.

Copper promotes good color in many minerals like azurite and malachite. If copper is present in non-copper species that might otherwise fluoresce, they will not. Copper quenches the fluorescence, but not always.

Normally, adamite is just about colorless but a little copper gives it that rich lime green color. Mexican adamite will fluoresce a bright green color because of the uranyl ion. The fluorescent response varies from brilliant green to no response at all. It all depends on the copper-uranyl relationship controlling the effects of ultraviolet.

Another quencher is iron. But again we find a conundrum. Iron minerals don’t fluoresce. But the iron in trace amounts of a mineral can be an activator as in some feldspars like anorthoclase. It can also be an activator in petalite and pectolite, though they tend to react better with other activators.

Unknown Activators

There are still a great number of minerals that fluoresce because of some unknown activator. A particular mineral species may or may not fluoresce depending on where it is found. This is what makes collecting fluorescent minerals so exciting. Coupled with the wide range of ultraviolet equipment, and the continuing discovery of more mineral species that fluoresce, the hobby will continue to grow.

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

The post What Makes Minerals Fluorescent? first appeared on Rock & Gem Magazine.

Many beautifully clear and well-formed crystals are currently on the specimen market from Charcas, Mexico.

Danburite forms in varied geological environments but is most common in contact metamorphic zones, where it forms under high temperatures. It was originally named for the town of Danbury in Fairfield County, Connecticut. There, it was discovered and described in 1839 by American mineralogist Charles Upham Shepard (1804-1886). This original “type” locality is now completely built over and thus no longer accessible to would-be collectors, but danburite also has been found in Mexico, Japan, Madagascar, Myanmar, Russia, Italy, Tanzania, and Bolivia.

At Mohs hardness 7 to 7.5, danburite is fairly hard and can be faceted into gemstones with a vitreous luster, although cut stones may lack the “fire” of, say, a truly fine topaz crystal. Large facet-grade specimens are somewhat rare (most cut specimens range 1 to 5 carats), making this an unusual gemstone in the jewelry market, where it is little known.

Faceted pieces more often are sought by mineral collectors than by connoisseurs of fine jewelry. As a gemstone, danburite has good clarity, strength, and light dispersion.

In addition to colorless or milky-white varieties, it sometimes is yellow, golden-yellow, yellowish-brown, beige or tan, or peachy pink, and such colored specimens make for wonderful faceted gems. However, “cleaner” colorless varieties tend to be more highly sought and valued.

Danburite sometimes exhibits a blue-white to bright sky-blue color under longwave ultraviolet light and also exhibits phosphorescence. That is, it holds and exhibits an “after-glow” for a brief period after a UV lamp has been shown upon it, then flicked off.

For all these reasons, danburite makes a perfect addition to your mineral collection!

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The post Exploring Danburite first appeared on Rock & Gem Magazine.

If you were to ascribe a motto to the interest of rockhounding, lapidary, and the like, what phrase would you select?

Asking that question of Erik Rintamaki of Yooperlite fame, one could expect a few responses, but carpe diem (loosely translated as “seize the day”) seems to be the perfect phrase, whether he’s taking on a wildly unexpected Yooperlite and agate hunting excursion in January along the shores of Lake Superior, spending time tapping into all of his skills (natural and hard-fought) to better his YouTube channel and social media presence, or always striving to be present and never take any of the opportunities for granted.

To recap, Rintamaki has been hunting Yooperlites (a name he coined) since he discovered the glowing beauties along the shores of Lake Superior in Michigan’s Upper Peninsula in 2017. What he discovered was a unique formation of a fairly common element, fluorescing sodalite. The discovery of this unique find by a self-proclaimed “joe schmo rockhound” attracted the attention of geologists, mineralogists, rockhounds, educators, news media, and people who simply found the glowing rocks to be fascinating. So several people on the planet have, let’s say, become fans of the glowing rocks.

Since his discovery and naming of the glowing rocks, Rintamaki has been a happily busy person. Before we go any further, let’s talk names. “Yooper” is the abated abbreviation of “U.P.” for Michigan’s Upper Peninsula — “Yoopers” are the area’s colloquial citizenry, as explained in an article by Wayne Peterson, published in the March 2019 issue of Rock & Gem. “Lite” refers to the rock’s fluorescent properties from sodalite. Together, it forms Yooperlites.

We caught up with Rintamaki recently to mine his experience and intellect for tips and hints about how he has made the most of the opportunities presented. At a time when the world continues to deal with the results and impact of COVID-19, there has been a mix of outcomes for businesses and individuals within the rockhounding and lapidary community. Some have flourished with online sales and on-site dig excursions, while many others have experienced lost income, lack of connection to others, and lost opportunity. Hopefully, some of the insight provided by the man who started the Yooperlite craze will inspire and bring a sense of hope.

“I take this very, very, very seriously, because I’ve now become like a folk hero for the rockhounding community,” said Rintamaki, who began collecting rocks before he could steadily walk the beaches of Lake Superior. “Because I’m just an average joe schmo. I’m not a geologist, I’m not a scientist, and I’m not a doctor, but I found something and did something any average rockhounder can do.”

BASING A BUSINESS ON A PASSION

Growing up in the Upper Peninsula, he still has the very first rock he collected. His mother, Penny Nantell, recorded the info on the rock, which he found while hunting with his dad.

“Every spring, as soon as there were little pockets of rock where the ice had melted on the beach, our dad (Ray Rintamaki) was having us out there with him – we’d be climbing rocks and also looking for rocks with him,” said the younger Rintamaki, whose grandfather Vilio Rintamaki, was also a rockhound and a jewelry artist who owned Mac’s Jewelry in Newberry, Michigan, and imparted his love of rocks to his son, Ray.

One of the many things that 2020 reiterated for Rintamaki is the truth and importance of expecting the unexpected. Instead of attending 30 shows, as he had planned, he attended one – the Tucson Gem and Mineral Show. However, his tour spots filled up in 2020. He offered just under 40 dates, between July and October, which he conducts himself, and they were full. With his 2021 tour dates posted (things get started July 7), now is the time to reserve a space.

PREPARING FOR THE UNEXPECTED

Having his online business in place and a well-defined system made a difference for this “one-man-band,” who does have help from his wife, Angela, when it came to selling Yooperlites and gear, and fulfilling orders, he said.

Sales at his store, www.yooperlites.com, jumped from $100 to $2,000 per day after news of the COVID-19 pandemic spread. Having a website that was well organized and one he was familiar with operating has made a significant difference, he added, explaining that January 2021 saw his site generate three times the sales of January during other years. Plus, having inventory on hand is what makes much of that possible.

Hunting Tip: Be sure you know the localities you are hunting and whether they are public or private property. Also, make sure you’ve researched the laws mandating what and how much of the geological material you find you can keep. For example, in Michigan there is something called the 25-pound rule. This means you can keep 25 pounds of rocks per person, per year, that are found on state property. Each state and even region is different, but doing research up front is critical and respectful, Rintamaki advises.

Remember the tip about expecting the unexpected? Another great example of that is the fact that Rintamaki has spent at least a couple of early morning hours (between midnight and dawn) on the shores of Lake Superior hunting rocks in January of this year.

“There’s no such thing as winter Yooperlite hunting.” said Rintamaki. “Normally, that is. However, 2021 winter is the weirdest winter ever. Right now, we have 12 inches of snow, and normally we have six feet of snow.

“It’s the strangest winter I have ever seen. I was at the beach twice in January and found stones on the 5th and the 12th. Never have I done that.”

See…carpe diem.

He’s also invested more time and effort in developing videos for his YouTube channel and sharing his adventures and opportunities via social media, he said. Again, as a one-man-band, he handles the videography, voiceovers, music, and editing of his videos. With a degree in musicianship from the now-defunct McNally Smith College of Music in Minnesota, Rintamaki, who used to travel and play music for a living, is able to incorporate his musical chops into videos showcasing another of his loves, Yooperlites. In 2020, he had just over 1,000 subscribers to his channel, and as of the first week of February 2021, he crossed the 10,000-subscriber mark, which also places him in the arena of being able to monetize his efforts.

While the adventures, excursions, and opportunities are a mix of predictable and wildly unexpected, Rintamaki wouldn’t have it any other way and strives to make certain that all of these things contribute to his main purpose, “hooking the next generation on rockhounding.”

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The post Seize the Day in Rockhounding first appeared on Rock & Gem Magazine.