Darapskit is a mineral , double- nitrate crystalline hydrate — sodium sulfate of the island structure of Na 3 (NO 3 ) (SO 4 ) · H 2 O. Named after L. Darapsky (1857-1916), a German-Chilean chemist and mineralogist from Santiago Chile .
| Drapskit | |
|---|---|
 Darapskit from Chile | |
| Formula | Na 3 (NO 3 ) (SO 4 ) · H 2 O |
| Physical properties | |
| Colour | Colorless |
| Color features | White |
| Shine | Glass |
| Transparency | Transparent |
| Hardness | 2.5 |
| Cleavage | Completed by {010} |
| Density | 2.2 g / cm³ |
| Syngony | Monoclinic |
| Refractive index | n α = 1.388 n β = 1.479 n γ = 1.486 |
Content
Properties
Colorless lamellar crystals of the monoclinic system , well soluble in water. Mohs hardness 2.5. Composition (%): Na 2 O - 37.94: N 2 O 5 - 22.04; SO 3 - 32.67; H 2 O - 7.35.
Deposits
It was first described in 1891 by Dietze ( Dietze ) [1] as a mineral in the Pampa del Toro nitrate deposits ( Chile , Antofogasta Province). One of the main minerals of some Chilean saltpeter deposits, mainly found in cavities or cracks. It is found together with sodium nitrate , astrakhanite , halite and anhydrite .
Notes
- ↑ Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 19: 445