Moonstone (gemstone)
Moonstone is a sodium potassium aluminium silicate ((Na,K)AlSi3O8) of the feldspar group that displays a pearly and opalescent schiller. An alternative name for moonstone is hecatolite.
| Moonstone | |
|---|---|
| General | |
| Category | Orthoclase variety |
| Formula (repeating unit) | (Na,K)AlSi3O8 |
| Crystal system | Monoclinic |
| Identification | |
| Color | Can be numerous colors, including blue, grey, white, pink, peach, green and brown, as well as colorless |
| Cleavage | perfect |
| Fracture | uneven to conchoidal |
| Mohs scale hardness | 6.0 |
| Luster | Opalescent |
| Streak | white |
| Specific gravity | 2.54–2.66 |
| Optical properties | for orthoclase and sanidine, biaxial (–); for oligoclase, biaxial +/– |
| Refractive index | 1.518–1.547 |
| Birefringence | 0.005–0.01 |
| Dispersion | 0.012 |
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.