Kogarkoite
| Kogarkoite | |
|---|---|
| General | |
| Category | Sulfate mineral |
| Chemical formula | Na3(SO4)F |
| Strunz classification | 7.BD.15 |
| Crystal symmetry | Monoclinic, pseudorhombohedral Space group: P21/m |
| Unit cell | a = 18.07 Å, b = 6.94 Å, c = 11.44 Å; β = 107.72°; Z=12 |
| Identification | |
| Color | Colorless, pale sky-blue, pale pink, lilac |
| Crystal habit | Tabular crystals, granular, earthy aggregates |
| Crystal system | Monoclinic |
| Twinning | Common |
| Mohs scale hardness | 3.5 |
| Luster | Vitreous to dull |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 2.66 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.439 nβ = 1.439 nγ = 1.442 |
| Birefringence | δ = 0.003 |
| 2V angle | Small, approaching zero |
| Ultraviolet fluorescence | Cream to pale blue under SW UV and green under LW UV |
| Solubility | Slowly soluble in water |
| References | [1][2][3] |
Kogarkoite is a sodium sulfate fluoride mineral with formula Na3(SO4)F. It has a pale blue color. The specific gravity is about 2.67 and the hardness is 3.5. The crystall system is monoclinic. Kogarkoite is named after the Russian petrologist Lia Nikolaevna Kogarko (1936-) who discovered the mineral.
[edit] Discovery and occurrence
Kogarkoite was first described in 1973 for an occurrence on Alluaiv Mountain, Lovozero Massif, Kola Peninsula, Russia.[2] On Alluaiv it occurs in pegmatitic veins in nepheline syenite. It occurs with sodalite in syenite xenoliths in an alkali intrusive complex at Mont Saint-Hilaire, Canada. In Hortense Hot Spring, Chaffee County, Colorado, it occurs as a sublimate.[1] It occurs at Lake Natron near Ol Doinyo Lengai, Tanzania and Suswa Volcano, Lake Magadi, Kenya.[2][1]
[edit] See also
[edit] References
| This article about a specific sulfate mineral is a stub. You can help Wikipedia by expanding it. |
