Template:Sardonyx
From The Gemology Project
Revision as of 01:51, 10 November 2006 by Africanuck (talk | contribs)
Sardonyx | |
---|---|
Chemical composition | Silicon Dioxide SiO2 |
Crystal system | Trigonal |
Habit | edit me |
Cleavage | poor |
Fracture | very brittle, conchoidal |
Hardness | 7 |
Optic nature | edit me |
Refractive index | 1.544 - 1.553 |
Birefringence | 0.009 |
Dispersion | 0.013 |
Specific gravity | 2.65 |
Lustre | Vitreous |
Pleochroism | None |