Difference between revisions of "Amethyst"
From The Gemology Project
Africanuck (talk | contribs) |
Africanuck (talk | contribs) |
||
Line 1: | Line 1: | ||
− | { | + | {{amethyst}} |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− |
Revision as of 23:36, 13 September 2006
Amethyst | |
---|---|
Chemical composition | Silicon dioxide SiO2 |
Crystal system | Trigonal |
Habit | Prismatic |
Cleavage | Poor |
Fracture | Conchoidal |
Hardness | 7 |
Optic nature | Uniaxial + |
Refractive index | 1.544 - 1.553 |
Birefringence | 0.009 |
Dispersion | Low, 0.013 |
Specific gravity | 2.63 - 2.65 |
Lustre | Vitreous |
Pleochroism | Weak to strong |