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Chinese Blue Fluorite floating on a bed of druzy quartz

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.

Beautiful cubic clear translucent fluorite specimen on matrix

By Ed Uthman from Houston, TX, USA – Fluorite, CC BY 2.0,

Fluorite crystals (blue) with Pyrite (gold-coloured), photographed at the National history museum in Milan, Italy

By Giovanni Dall’Orto – Own work, CC BY-SA 2.5 it,

Fluorite from Hardin County, Illinois. A slice has been cut from a large Illinois fluorite crystal, then polished on both sides, to show the incredible zoning inside the crystal, tracking its growth like rings on a tree! Note the band of light teal blue that formed as the solution changed inside the pocket while the crystal was growing.

By Rob Lavinsky, – CC-BY-SA-3.0, CC BY-SA 3.0,

Green fluorite twinned crystals on matrix found from Diana Maria mine, Rogerley quarry, Stanhope, County Durham, England

By Ivar Leidus – Own work, CC BY-SA 4.0,

Yellow Fluorite from the Valzergues Mine, Aveyron, Midi-Pyrénées France

By Didier Descouens – Own work, CC BY-SA 3.0,

Fluorite from Elmwood mine, Carthage, Central Tennessee Ba-F-Pb-Zn District, Smith County, Tennessee, USA. A fine, translucent fluorite crystal perched on the edge of a shard of matrix sparkling with microcrystals of dolomite. Fluorite is complete on front, cleaved on back where removed from pocket wall. 

By Rob Lavinsky, – CC-BY-SA-3.0, CC BY-SA 3.0,

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