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Fluorite, CaF2

What is that crystal? You know the one I’m talking about! Sometimes it’s blue, purple, yellow, green, clear or some mix swirl of any or all of those colors. Sometimes it lights up blue or green or purple when you shine that invisible light, ultraviolet light.

It usually looks like little rectangles maybe lying atop a druzy quartz surface, or on top of calcite or other minerals. Sometimes it’s botryoidal. It’s popular when carved into an eight sided shape that’s perfect for playing Dungeons & Dragons, but it’s carved into standalone points out of mega crystals looking like the kind of witchy or metaphysical talisman you would expect to have mystical or spiritual or otherworldly powers.

Fluorite, yeah that’s its name. Named after the Latin word fluere meaning “to Flow“, it has lent its name to the term for when a crystal exposed to ultraviolet light, seems to change color through florescence.

Technically speaking fluorite is a halide mineral that is the crystal form of CaF₂, and has a hardness between that of quartz and calcite. It is colorless when pure, but with impurities it takes on the many different colors it is known for. Besides being beautiful and used in jewelry and decoration it also is used industrially to produce smelting flux, certain glasses and enamels, and as a source for hydrofluoric acid. It also has optical properties making it valuable as a lens in microscopes, telescopes and especially where far-ultraviolet and mid-infrared spectrums are used.

Fluorite has the nickname “the most colorful mineral in the world” because of the wide range of colors imparted by different impurities. Fluorite can appear in every color in the rainbow as well as white, black, and colorless.

Fluorite is one of my favorite minerals. One of the prized specimens in my collection is a Chinese (insert location information ) example of blue fluorite floating on a druzy quartz wing of matrix material with smaller blue fluorite crystals all over the piece from Xinyang, QianZhou, Fuhian, China. I acquired the specimen some years ago from an estate and some thing about the statuesque shape, the colors, and the general positioning of the largest pieces cubic blue fluorite looking like a pair of eyes on some alien cephalopod, staring back at me seized on my imagination.

Check out our collection of fluorite for sale on the Georarities Fluorite product page!

The other night, I was discussing Eddie Murphy with a friend. Murphy, whose career has been up and down over the past 10 years had a bit of a comeback in 2019 with the film Dolemite is My Name. This is a comedic-bio-pic Netflix file is about blaxploitation film-maker Rudy Ray Moore. Nothing about the movie, except part of the name, Dolemite (which actually refers to a film that Rudy Ray Moore, played by Murphy, made in the 1970s of the same name) has anything to do with geology. But once I started thinking about dolomite, I went down the rabbit hole.

I thought I knew what dolomite. After all, I have some of it in my collection. It’s that creamy mineral you find in Indiana right? It turns out the history of the name and it applies to is a bit torturous and complicated. The name dolomite begins in the 18th century. A french geologist named Dieudonné Sylvain Guy Tancrède de Gratet de Dolomieu usually known as Déodat de Dolomieu, discovered in the old city of Rome, and later during a visit to the Alps of northeastern Italy, a calcareous rock which, did not effervesce when exposed to weak hydrochloric acid. This was unlike limestone. Dolomieu published this discovery in the journal Journal de Physique in March of 1792. The calcareous mineral he described was eventually named after him, as dolomite. In addition, a mountain range in northeastern Italy, part of the southern limestone alps, was named The Dolomites, also after Dolomieu.

But what exactly was it that Dolomieu discovered? Limestone had been used as a building material for thousands of years. The ancient Egyptians used limestone to build the pyramids of Giza and the Great Sphinx. The Maya of ancient Mexico used it for carving. The ancient Athenians used it to build the Parthenon on the Acropolis in Athens during its golden age. The Romans used it to build the Colosseum in Rome. Jerusalem stone (limestone) was used to build ancient Jerusalem from mines located near the neighborhood of Yemin Moshe. But this new mineral, despite some similarities clearly wasn’t limestone. The stronger resistance to HCL proved that.

Both limestone and the new mineral, it turns out, were typically sedimentary carbonate minerals. Limestone is typically composed of calcite and aragonite, both forms of crystallized CaCO₃. The new mineral turned out to be an anhydrous form of CaMg(CO₃)₂, and it turns out that the magnesium makes all the difference. For a long time the new mineral, named dolomite in Dolomieu’s honor, was applied to both the crystal and rock formations of the mineral. Confusion about the term Dolomite, which now referred to three distinct things, persisted until 1948 when geologists changed the name of the rock formation of calcium magnesium carbonate to dolostone. Dolomite from that point on only refers to the mineral and not the rock formation. The “Dolomites” is used to refer to the mountain range.

Even though the mineral was discovered in Europe, it is found across the world include Spain, China, Brazil, and Ohio among other places. Spain used to be the source of the finest dolomite crystals, but now Brazil and China also produce world class specimens. Dolomite also appears as a bed on which showier crystals display – see the spakling example below of Dioptase from Tsumeb mine, Namibia, formerly of my collection.

Click here to check out our selection of Dolomite for sale.

_{Main photo by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10148460}

Everybody loves the color purple, a color has an old association with royalty.  The dye known Tyrian purple was a luxury item.  Created from the secretions of a certain sea snail it was famous for the purple color not fading over time but in fact become me even brighter and more beautiful.  Alexander the great and his successors or the color purple is a symbol of royal authority.  They say the King Solomon decorated the ancient Jewish temple of Jerusalem with purple, and the roman Republic the color was restricted to high ranking members of the elite.  During the time of the Roman empire, production of the color would be nationalized, and use of it would be restricted to the emperor, giving rise to the phrase “raised to the purple” meaning becoming emperor.

It’s no surprise that the love of the color purple resists even today.  Some of the most beloved crystals purple in color.  In this article we will list the number of the more popular than commonly found purple crystals and stones.

Perhaps the most popular purple crystal is Amethyst, a lilac colored variety of quartz.  The name derives from ancient Greek and refers to a belief that the stone protected its owner from becoming drunk.  The crystal was often worn by the ancient Greeks, and make large drinking vessels from it to protect the drinker from drunkenness.  The purple color in amethyst quartz comes from impurities of iron and occasionally other transition metals and irradiation.  The ancient Egyptians and romans used amethyst as a gemstone, and often carved it in the intaglio style.  The majority of amethyst today comes from Brazil and Uruguay.  Amethyst can be found in crystals ranging from very small to very large, and it will oftentimes form large crystals, crystal clusters, and even geodes.

Check out our amethyst for sale.

Charoite is a rare, usually translucent silicate mineral ranging in color from lavender to purple.  It does not form individual crystals and is only found in Siberia.

Pink two purple and color, lithium rich Lepidolite is a typically soft mica mineral.  Only when lepidolite is associated to hard quartz can it be cut and polished for use as a gemstone.

Fluorite comes in many colors but purple is the most common.  Some of the best examples originated in China, Morrocco, and Illinois.  Fluorite can be in any number of shapes, including cubes, octohedrons, and botryoidal forms.  Oftentimes Fluorite will glow under ultraviolet light (i.e. fluoresce).  Fluorite is popular with collectors as it’s usually reasonably priced because it’s fairly common.

Sugilite is an uncommon grape jelly colored cyclosilicate mineral.  Is often used a gemstone, and some people believe that it has spiritual healing powers.

Grape agate is an uncommon botryoidal mineral.  Most of it is purple in color, although we have seen blue varieties.  It is neither an agate nor a chalcedony.  It is instead spherical nodules of amethyst that formed around seed crystals and which interlinks as it grows.  It is beautiful but expensive, but originates in Indonesia.

Tanzanite is a beautiful crystal that can appear purple, blue, or burgundy depending on the orientation of the crystals.  It is named after Tanzania, in which it is found.  It’s a variety of zoisite that contain vanadium.

Jade is a beautiful and highly desirable material. It’s valued for the fabulous and magnificent works of art that are created from it, and for the deeper meanings people attach to it. In different periods of Chinese history Jade was associated with heaven, as a symbol of authority. Confucius used jade into a metaphor for virtue, kindness, wisdom, justice, civility, music, sincerity, truth, Heaven and Earth. But sometimes, its not the cultural symbolism or monetary value of an object which is, but the personal sentiment. This story is one such example.

The story begins with the December 7th, 1941 Japanese attack on Pearl Harbor which brought the United States into the Second World War. Through the first six months of the war the United States suffered a series of defeats – in the Philippines, Wake Island, and the Java Sea. Seeking a way to achieve a victory to raise American morale – and deal a blow to Japanese morale, a plan was conceived whereby the Japanese home islands would be bombed by U.S. Army Air Force B25-B bombers loaded onto and launched from U.S. Navy aircraft carriers.

The bombers were loaded onto the carriers Hornet and Enterprise on April 1st, 1942. The aircraft were launched 10 hours ahead of schedule on April 18th when the carrier task force was sighted by a Japanese ship. The aircraft dropped their bomb loads over Tokyo and other Japanese cities, causing minor damage to their targets but inflicting a major shock to the Japanese military and government. The consequence of launching earlier was the planes were launched 200 miles further from Japan than planned, making them unable to reach the landing bases prepared by Chiang Kai-Shek’s Nationalist Chinese forces – an ally against Japan. 15 of the 16 planes managed to reach the Chinese coast thanks to a lucky tailwind, the 16th plane reaching the Soviet Union.

Unfortunately, none of the places reached safe Chinese bases, instead running out of fuel in areas occupied by or threatened by Japanese troops. Chinese locals and military forces helped hide and rescue the American crews. The Chinese, who had already been at war with Japan for years before this, and had been taking blows from the Japanese were greatly appreciate of the counterblow delivered by the Americans. One of the rescued pilots, Lt. Travis Hoover, was presented with a gift by Mr. Tung-Sheng Liu, a Chinese district commissioner who also acted as an interpreter and guide for Hoover’s crew, helping them reach safety. The gift was a delicately carved piece of Jade. Today, this Jade is located and on display with artifacts from the Doolittle Raid at the National Museum of the United States Air Force, located on the Wright-Patterson Air Force Base in Dayton, Ohio.

The image for this post shows the U.S. Army Air Force crew of the North American B-25B Mitchell bomber (s/n 40-2292, Lt. Travis Hoover). They had left the aircraft carrier USS Hornet (CV-8) as No. 2 plane of the “Doolittle Raid” on 18 April 1942 and bombed Tokyo. After running out of fuel the plane crashed near Ningpo, China. Mr. Tung-Sheng Liu (劉同聲, third from right in white jacket) stands with the crew of Lt. Travis Hoover. He helped these men escape capture following the Doolittle Raid. He later immigrated to the United States and was one of four individuals names as honorary Doolittle Raiders.

If you are looking for Jade, check out our selection of Jade for sale by clicking here.

_{Image Credit: By USAF – National Museum of the U.S. Air Force photo 100907-F-1234S-001, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11422843}

Herkimer County, lying north of the Mohawk river in upstate New York, is known for two things: being the one of two production sites for the Remington Arms Company, and being the source of Herkimer Diamonds. Herkimer diamonds are actually unusual, naturally double terminated transparent quartz, whose clarity and natural faceting has led to the diamond nickname that range from colorless to smoky. These unusual crystals have eighteen faces – six on each end, and six in the middle. and were discovered in dolomite outcroppings by early settlers mining the dolomite, or plowing fields. Any number of inclusions, from microscopic to visible, can occur in the crystal including: salt, water, dolomite, liquid petroleum, calcite, pyrite, sphalerite, and even quartz. While similar naturally double terminated and faceted quartz can be found in other locations, only the material from Herkimer County is called Herkimer Diamonds.

The native Mohawks knew of and valued the crystals as well, and collected them from stream sediment using the material for tools or trading with other tribes. Eventually, “Herkimers” were supplanted among the Mohawk by glass beads brought by traders and settlers.

It’s obvious that Herkimer diamonds are named after their place of origin, Herkimer County, but less obvious is their to the American Revolution, and through that to pop culture. Herkimer County, you see, was named after General Nicholas Herkimer, an American Patriot Militia leader of the American Revolution. An American born grandson of German Palatine immigrant Georg Herchheimer, he grew up in the Mohawk Valley region speaking English, German, and Mohawk. He acquired the rank of Captain in the local militia fighting in the region during the Seven Years war, a global struggle between France and England and their allies known locally in North American as the French and Indian War. He held some slaves, not unlike other settlers and their Mohawk neighbors in the region.

Herkimer’s fame derives from his actions during the siege of Fort Stanwix during the Saratoga Campaign of the American Revolution. By this time promoted to Brigadier General, his force was ambushed on August 6, 1777 by British regulars, Tory Militia and Mohawk warriors while marching to relieve Fort Stanwix. The engagement, later known as the Battle of Oriskany was one of the bloodiest battles of the Revolution. With his horse shot, and wounded in the leg, General Herkimer directed the battle while propped up against a tree, rallying his two times to prevent panicked retreats. When his force withdrew his leg was dressed and he was carried home in a litter, but the wound became infected. The decision to amputate the leg was delayed ten days and the surgeon who was performed it was inexperienced because the brigade surgeon had himself been wounded in the fighting at Oriskany. The operation went poorly and General Herkimer bled to death.

In addition to being a bona fide war hero, General Herkimer had his own Hollywood moment. Walter Edmond’s 1936 novel Drums Along The Mohawk was adapted into the 1939 John Ford film of the same name. General Herkimer is a character in both works. He is portrayed in the film by actor Roger Imhof, alongside the leads Henry Fonda and Claudette Colbert. Not too shabby for war hero whose great claim to fame was 244 years ago!

In a tragic footnote, the general’s younger brother militia Captain Johan Jost Herkimer was also at the Battle of Oriskany when the general’s column was ambushed – but with the other side. Johan Jost was a loyalist who supported the king during the revolution and was a Captain in the Tory militia.

_{Topmost photo By James St. John – https://www.flickr.com/photos/47445767@N05/50717613196/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=97564957}

Goldstone. You know it, that gorgeous with a glittering star field that comes in blue, red, green or purple. It’s used for jewelry. It looks wonderful on your desk as a paperweight, or on a shelf as an eye-catching display object. Kids love it because of the sparkles. Adults love it too – take a deep look into a dark blue example and after a few moments you lost in what feels like the star field in the opening of Star Wars. But what exactly is Goldstone, and were does it come from? What mine do they dig the stuff out of?

Well, as it turns out, it comes from no mine. Even though it sure likes an amazing example of mother nature’s artistry, perhaps helped along with human assistance and a tumbler, it is actually man made. That’s right, it is synthetic. But not synthetic in a bad way, and certainly not synthetic in the modern sense such as with Ruby, which is created by fusing potash alum at a high temperature with a little chromium as a pigment. No, Goldstone is no lab or factory born. It’s birth is traced to the hand of the artist and artisan. But before we look at origins, let’s look at exactly what Goldstone is.

What is Goldstone?

Goldstone is form of man-made glass. It has a glittering, metallic character luster caused by flat faced and highly reflective inclusions of copper. The luster is caused by heating molten glass to the temperature necessary to dissolve copper oxide granules added to the molten glass. The melt is then cooled slowly allow the copper ions to grow into uniformly dispersed octohedral shaped crystals. The size of the copper crystals formed is directly related to the length of time taken to coll the melt. The longer the cooling, the larger the crystals. It is these copper crystals that creates the glittering luster.

But wait, you ask. What make gives the goldstone it’s red, or blue, or green, or purple color in which the copper stars are fixed? Well, the answer to that differs with each color of goldstone. Glass itself is typically colorless, and goldstone is no exception. Red goldstone is red because of reflection off the copper crystals. Blue, green, and purple goldstone use metals other than copper, but the background color doesn’t come from the metal, but rather from the addition of other elements to the glass itself. The blue in blue goldstone is caused by the addition of cobalt to the glass, green from the addition of chromium, and purple from the addition of manganese. Goldstone without copper is easier to work with when reheated, because of less stringent reduction requirements and higher melting points of manganese and cobalt.

Regardless of the metal used to create the particular color of the star field pattern, the glitter effect is intensified when a piece of goldstone is moved under light, when a lighting source is moved over the goldstone, or when the observer is in motion relative to a piece of lighted goldstone. If that sound technical, then think of it like this. A lighted piece of goldstone gets a whole lot glitterier if either you move it, you move yourself, or you move the light.

History of Goldstone

Goldstone dates as far back as the period between the 12th and 13th centuries A.D., the earliest known goldstone object being an amulet excavated in Iran with an inscription dedicating it to one of the rulers of Syria during that period. It was being manufactured in Italy by the 17th century, in Murano and Venice. The Motti family of Venice was granted an exclusive license to manufacture the material by the Doge (think “Duke”, they both originate from the same word) of Venice. The Chinese were making goldstone around the same time as the Italians with bottles made of the material by the Imperial Workshop handed out by the Qing Emperor’s court as gifts and rewards.

Goldstone is actually a more recent name for the material. An earlier common name for it aventurine glass, based on the Italian “avventurina” meaning “by chance” or “accident” in reference to the tale that the discovery of how to make the material was an accident. Goldstone should not be confused with the mineral aventurine, which is a feldspar or quartz with a mica inclusion that can also be glittery. In point of fact, the mineral was named after the goldstone because it’s glittery luster was reminiscent of of goldstone.

Party Tricks with Aventurine

So the heading is a bit of joke – there will be no party tricks discussed here. Instead let’s talk a little bit more about the name aventurine, the early name for goldstone. Besides gifting it’s name to the natural mineral aventurine, goldstone has lent it’s original to several technical terms used to describe that glittery loveliness goldstone is in possession so much of.

First is the term “aventurescence” which refers to the phenomena that occurs when a material with light-reflecting particles that produce a sparkly or glittery luster.

Then we have the term “aventurescent” which describes (also see the definition of adjective) materials that exhibit the phenomena of aventurescence. Usage examples include: aventurescent quartz, aventurescent feldspar, aventurescent iolite, and aventurescent soda pop. Actually that last item is joke, but soda pop beside shimmery and bubbly right after pouring does remind one of goldstone, well, a bit.

Cousins of Goldstone and Other Curious Facts

There are other types of glass that have some similarity to goldstone. For example, there is transparent red copper ruby glass and also opaque “sealing wax” purpurin glass, all of which have beautiful reddish colors of which are created by colloidal copper. The key difference among these is the size of the copper crystals. Goldstone has macroscopic (large) reflective crystals; purpurin glass has microscopic (small) opaque particles; copper ruby glass has submicroscopic (very small) transparent nanoparticles.

The outer layers of a batch of goldstone often has a duller color and less glittery goodness, characteristics usually dues to poor crystallization which decreases the size of the reflective copper crystals and makes the surrounding glass more opaque with non reflective particles. This may also be due to partial oxidation of the copper which may lead the crystals dissolving leading to a transparent blue-green glass.

Sometimes goldstone only displays the glittering effect from two directions rather than from any vantage point.

Goldstone is actually popular for cutting jewelry. As rough pieces, it is usually sold as broken chunks and as slabs suitable for cutting cabochons. Smaller pieces might be rock tumbled, while larger chunks might weight over 50 pounds. A single batch of goldstone usually weighs in at 100 pounds or more, before being cut into smaller chunks. The quality of the goldstone due to variability from the manufacturing process will dictate the end use.

Metaphysical, Spiritual, and Healing Properties of Goldstone

Even though goldstone is synthetic, many believe it has spiritual or metaphysical properties, and can be used in physical healing. The specific properties and effects of the goldstone vary depending on who you consult, and their particular perspective. One thing is certain, contemplating the start field of a beautiful example of goldstone can be a calming and meditative experience!

We sell goldstone. Check out our selection, or visit us in-person.

_{Top photo depicting a piece of ‘red’ or ‘brown’ Goldstone glass under magnification to show the crystals inside – by Albionfireandice – website, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=104498606}