Global InformationNuummite information
| Nuummite | |
|---|---|
 | |
| General | |
| Category | Mineral variety |
| Formula (repeating unit) | (Mg 2)(Mg 5)Si 8O 22(OH) 2 |
| Identification | |
| Formula mass | 780.82 gm |
| Color | Black, grey |
| Twinning | None |
| Cleavage | Perfect on 210 |
| Fracture | Conchoidal |
| Mohs scale hardness | 5.5 - 6.0 |
| Luster | Vitreous/glossy |
| Diaphaneity | opaque |
| Specific gravity | 3.18–3.37 |
| Density | 2.85 - 3.57 |
| Optical properties | Biaxial (–) |
| Refractive index | 1.598 - 1.697 |
| Birefringence | 0.0170 - 0.230 |
Nuummite is a rare metamorphic rock that consists of the amphibole minerals gedrite and anthophyllite. It is named after the area of Nuuk in Greenland, where it was found.[1][2][3]
- ^ Geological Survey of Denmark and Greenland (GEUS), ed. (2008), "Minerals in Greenland" (PDF), Geology and Ore (in German), no. 12, p. 12, archived from the original (PDF) on 2011-12-21, retrieved 2012-11-08
- ^ "Nuumite". ClassicGems.net. Retrieved 1 December 2012.
- ^ "Gemstones of Greenland" (PDF). Geology and Ore. Geological Survey of Denmark and Greenland (GEUS). January 2007. Archived from the original (PDF) on 24 February 2013. Retrieved 4 December 2012.