By Géry Parent (collection perso.) [see page for license], via Wikimedia Commons
A faceted vanadinite may be considered a tremendous rarity. Fewer than ten such gems may have been cut. This is unfortunate since the color is rich and beautiful. Arizona crystals tend to be very small, but the ones from Morocco reach a size of several inches.
| Data | Value |
|---|---|
| Name | Vanadinite |
| Is a Variety of | Apatite |
| Crystallography | Hexagonal. Crystals hexagonal prisms, also tabular, filiform, skeletal. |
| Refractive Index | 2.350-2.416 |
| Colors | Red, orange, orange-red, brownish red, pale yellow, yellow, brownish. Rarely colorless; zoned. |
| Hardness | 2.5-3 |
| Fracture | Conchoidal |
| Birefringence | 0.066 |
| Cleavage | None |
| Dispersion | 0.202 |
| Stone Sizes | Faceted gems are extremely rare and always small (less than 1 carat). The material is not normally cut into cabochons because it is almost always in good crystals that are prized by collectors. Potential faceting material would most likely come from Arizona or Morocco. |
| Luminescence | None. |
| Luminescence Present | No |
| Absorption Spectrum | Not diagnostic. |
| Formula | Pb5(VO4)3Cl + P, As. |
| Pleochroism | Very slight, shades of orange and yellow. |
| Optics | e = 2.350; o = 2.416. Uniaxial (-). |
| Optic Sign | Uniaxial - |
| Luster | Resinous to subadamantine. |
| Specific Gravity | 6.88; range 6.5 - 7.1. |
| Transparency | Transparent to opaque. |
Streak:Â White to yellowish.
Occurrence: Secondary mineral in the oxidized zone of ore deposits, especially lead deposits. Arizona (Apache Mine, Mammoth Mine, elsewhere); New Mexico; California; Utah; South Dakota; Colorado.
Chihuahua, Mexico; Algeria; Scotland; Argentina: Tunisia;
USSR; Austria; Sardinia.
Mibladen, Morocco: large red to brown crystals.
Comments: A faceted vanadinite may be considered a tremendous rarity. Fewer than ten such gems may have been cut. This is unfortunate since the color is rich and beautiful. Arizona crystals tend to be very small, but the ones from Morocco reach a size of several inches.
Name: In allusion to the composition.
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