Saliotite
Saliotite is a rare colorless to pearl white phyllosilicate mineral in the smectite group with formula (Li,Na)Al3 (AlSi3O10)(OH)5.[1] It is an ordered 1:1 interstratification of cookeite and paragonite. It has perfect cleavage, a pearly luster and leaves a white streak. Its crystal structure is monoclinic, and it is a soft mineral with a hardness rated 2-3 on the Mohs scale.[1][2]
| Saliotite | |
|---|---|
| General | |
| Category | Silicate mineral |
| Formula (repeating unit) | (Li,Na)Al3 (AlSi3O10)(OH)5 |
| Strunz classification | 9.EC.60 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | C2/m |
| Unit cell | a = 5.15 Å, b = 8.91 Å c = 23.83 Å; β = 94.23°; Z = 4 |
| Identification | |
| Color | Colorless to white |
| Cleavage | Perfect on {001} |
| Mohs scale hardness | 2 - 3 |
| Luster | Pearly |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 2.75 |
| Optical properties | Biaxial (-) |
| Refractive index | nα = 1.580 - 1.590 nβ = 1.580 - 1.590 nγ = 1.590 - 1.600 |
| Birefringence | δ = 0.010 |
| 2V angle | 30° to 50° |
| References | [1][2] |
Saliotite was first described in 1994 for an occurrence in an outcrop of high grade schist north of Almeria, Andalusia, Spain. It was named for French geologist Pierre Saliot.[1]
References
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.