| Formula |
SiO2 |
| Molecular mass |
60.08 g/mol |
| admixture |
|
| IMA Status |
Valid, first described before 1959 (before IMA) |
| Systematics according to IMA (Mills et al., 2009) |
| Class |
silicates |
| Group |
quartz |
| Physical Properties |
| Color |
By itself, colorless or white due to cracking, impurities can be painted in any color |
| Dash color |
White |
| Shine |
Glass |
| Transparency |
translucent,transparent |
| Mohs hardness |
7 |
| fragility |
|
| Cleavage |
Missing |
| kink |
conchoidal |
| Density |
2.6-2.65 g/cm³ |
| Crystallographic properties |
| space group |
P31 2 1 |
| Syngony |
Trigonal |
| Twinning |
Dauphinian law, Brazilian law, Japanese law |
| Optical properties |
| optical type |
Single axis (+) |
| Refractive index |
nω = 1.543 – 1.545 nε = 1.552 – 1.554 |
| Birefringence |
δ = 0.009 |
| dichroism |
|
| optical relief |
Short |
| Dispersion of optical axes |
|
| Pleochroism |
Missing |
| Luminescence |
Fluorescent and triboluminescent, under UV – yellow-orange |
| Diffusion |
Low, 0.009 |