Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons
The blue color of linarite is magnificent, and it is a pity that large facetable rough has not been found. Clean areas of crystals are usually very small, and breakage in cutting due to the softness and cleavage of the mineral further complicates the salvaging of a large gem. This is a lovely collector item and an extremely rare one.
| Data | Value |
|---|---|
| Name | Linarite |
| Colors | Dark azure blue. |
| Crystallography | Monoclinic. Crystals prismatic; also in druses and crusts. |
| Refractive Index | 1.809-1.859 |
| Luster | Vitreous to subadamantine. |
| Hardness | 2.5 |
| Fracture | Conchoidal |
| Specific Gravity | 5.30 |
| Birefringence | 0.050 |
| Cleavage | Perfect 1 direction |
| Stone Sizes | Faceted gems over 1 carat are very rare. Anything over ½ carat is remarkably large for linarite. Crystals tend to be filled with fractures or are translucent and are usually very thin blades on rock. Grand Reef material has yielded cut gems in the 2-carat range. |
| Luminescence | None. |
| Luminescence Present | No |
| Transparency | Translucent to transparent. |
| Absorption Spectrum | Not diagnostic. |
| Formula |
PbCu(SO4)(OH)2. |
| Pleochroism |
Pale blue/medium blue/Prussian blue. |
| Optics |
a = 1.809; β = 1.838, γ = 1.859. Biaxial (-), 2V= 80°. |
| Optic Sign | Biaxial - |
Streak: Pale blue.
Optics: a = 1.809; β= 1.838, γ= 1.859.
Biaxial (-), 2V= 80°.
Occurrence: Secondary mineral in the oxidized zones of lead-copper deposits.
Blanchard Mine, Socorro County, New Mexico: California: Montana: Utah: Idaho: Nevada.
England: Scotland; Spain: Germany: Sardinia: Russia: Canada: Argentina: Peru: Chile: Japan: Australia: Tsumeb, Namibia.
Mammoth Mine, Tiger, Arizona: large crystals of fine color.
Grand Reef, Arizona: large crystals, some cuttable.
Comments: The blue color of linarite is magnificent, and it is a pity that large facetable rough has not been found. Clean areas of crystals are usually very small, and breakage in cutting due to the softness and cleavage of the mineral further complicates the salvaging of a large gem. This is a lovely collector item and an extremely rare one.
Name: After the locality, Linares, Spain.
IGS Newsletter
