Learn More About Fluorite Gemstone
What is Fluorite?
Crystallography |
Isometric. Usually in good crystals, cubes, octahedra, and other forms, often twinned; also massive, granular. |
Colors |
An extremely wide range is represented: colorless, purple (various shades), green (various shades), blue-green, blue, yellow to orange, brown (various shades), white, pink, red, brownish red, pinkish red, brownish black, black. Crystals are frequently color zoned. |
Luster |
Vitreous |
Fracture |
Quite brittle. |
Hardness |
4 |
Specific Gravity |
3.180; massive material with impurities 3.0-3.25. |
Cleavage |
Perfect 4 directions. Cleavage is octahedral, very easy. |
Dispersion |
0.007 (very low) |
Luminescence |
See "Identifying Characteristics" below. |
Transparency |
Opaque to transparent |
Absorption Spectrum |
U and rare earths are often present; spectrum reflects their presence. Spectra usually vague, however. Green material has lines at 6340, 6100, 5820, and 4450 and a broad band at 4270. |
Phenomena |
Color change (Very rare). |
Formula |
CaF2 |
Optics |
Isotropic; N = 1.432-1.434. |
Etymology |
From the Latin fluere, “to flow,” because it melts easily and is used as a flux in smelting. |
Occurrence |
In hydrothermal deposits; sedimentary rocks; hot springs; rarely in pegmatites; usually associated with sulfide ore deposits. |
Inclusions |
Mineral crystals, cavities (single, two, and/or three phase), healed fractures. |