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Cristobalite : SiO2, Fayalite : Fe2+2[SiO4] | |
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Couger Mine, Siskiyou Co., California, USA Obsidian(volcanic glass) cools too quickly, to crystallize. Thus, it is unusual to see minerals attached. The spheres of high temperature cristobalite(SiO2) are actually the result of devitrification, or loss of silica from the obsidian. Most unusual. 5.9 x 3.8 x 3.8 cm |
| © Rob Lavinsky | Photo ID: 40048 View Count: 286 |
Cristobalite : SiO2, Fayalite : Fe2+2[SiO4] | |
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Couger Mine, Siskiyou Co., California, USA This example of cristobalite on obsidian, created by devitrification of the obsidian, exhibits a large vesicle 2.5 cm across. 6 x 5.4 x 2.5 cm |
| © Rob Lavinsky | Photo ID: 40050 View Count: 281 |
Cristobalite : SiO2, Obsidian | |
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Couger Mine, Siskiyou Co., California, USA This is another unusual specimen of cristobalite on obsidian. The spheres of cristobalite are the result of devitrification of the obsidian. 6 x 5.9 x 2.5 cm |
| © Rob Lavinsky | Photo ID: 40049 View Count: 234 |
Cristobalite : SiO2, Fayalite : Fe2+2[SiO4] | |
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Siskiyou Co., California, USA This example of cristobalite on obsidian, created by devitrification of the obsidian, exhibits a large vesicle 3 cm across. SHOWY! 11.8 x 8.5 x 6.8 cm |
| © Rob Lavinsky | Photo ID: 39952 View Count: 228 |
Cristobalite : SiO2, Obsidian | |
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Couger Mine, Siskiyou Co., California, USA Lithophysae of Cristobalite up to 3cm of diameter in Obsidian (from Medicine Lake) - Overall size 8x6x5cm - July of 2001 |
| © Martins da Pedra | Photo ID: 46935 View Count: 213 |
Cristobalite : SiO2 | |
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Couger Mine, Siskiyou Co., California, USA Lithophysae of Cristobalite up to 3cm of diameter in Obsidian (from Medicine Lake) - Overall size 7x5x4cm - July of 2001 |
| © Martins da Pedra | Photo ID: 47886 View Count: 188 |
Cristobalite : SiO2, Fayalite : Fe2+2[SiO4] | |
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Couger Mine, Siskiyou Co., California, USA 13.4 x 9.9 x 6.2 cm. A visual and fine cabinet specimen of "eyes" of high-temperature cristobalite scattered in highly lustrous, jet-black obsidian from an uncommon California locale - Cougar Mine, Siskiyou County. Some of the "eyes" have faint hints of gemmy, micro-blades of fayalite, an olivine group mineral. Obsidian (volcanic glass) cools too ... |
| © Rob Lavinsky | Photo ID: 237494 View Count: 40 |
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Couger Mine, Siskiyou Co., California, USA 6.2 x 6.2 x 3.6 cm. A fine specimen featuring "eyes" of high-temperature cristobalite scattered in highly lustrous, jet-black obsidian from an uncommon California locale - Couger Mine, Siskiyou County. Some of the "eyes" have faint hints of gemmy, micro-blades of fayalite, an olivine group mineral. Obsidian (volcanic glass) cools too quickly, to ... |
| © Rob Lavinsky | Photo ID: 217451 View Count: 34 |
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Couger Mine, Siskiyou Co., California, USA 5.8 x 5.8 x 4.4 cm. A visual and showy specimen of a 2.5 cm "eye" of high-temperature cristobalite nicely set in highly lustrous, jet-black obsidian from an uncommon California locale - the Couger Mine, Siskiyou County. The "eye" has three clusters of gemmy, olive-green, micro-blades of fayalite, an olivine group mineral. Obsidian (volcanic glass) ... |
| © Rob Lavinsky | Photo ID: 254004 View Count: 23 |
Gold : Au | |
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Anna Johnson & Suprise Mine, Liberty District, Siskiyou Co., California, USA This gold specimen , wich weighs almost 1 ounce, is composed totally of small intergrown crystals. It is bright, lustrous, heavy and much rarer in dealers’ stocks than any California gold. It is most likely 20-30 years out of the ground and specimens of this weight are very rare! 3.4 x 1.9 x 0.9 cm |
| © Rob Lavinsky | Photo ID: 64370 View Count: 227 |
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