Nuummite
Nuummite (or Nuumite) is a trade name for a metamorphic rock consisting primarily of two amphiboles; Anthophyllite and Gedrite. It was originally found only in the Godthabsfjord area located in West Greenland near the capital of Nuuk. The chemical formula of Nuummite is (Mg2)(Mg5)Si8O22(OH)2 (Magnesium Silicate Hydroxide) and its molecular weight is 780.82 gm. This material has typically been a black base color with bright iridescent flashes of gold, yellow, copper, red, blue and green. The Hardness is 5.5 – 6.0 and the specific gravity 2.85 – 3.57 (g/cm3). Nuummite is an opaque material which exhibits a vitreous to glossy lustre when polished. A recent find in the Sahara Desert of Mauritania has produced material with iridescent flashes of deep blue Anthophyllite needles on a black opaque background. When coming to crystal habit of this stone is Crystals rare, to 25 cm; as bladed aggregates of unterminated prismatic crystals. Nuummite is not known to be treated or enhanced in any way. Commonly lamellar or fibrous, asbestiform. This new material discovered in 2009 has been called Sahara Nuummite or Jenakite.
Nuummite is of volcanic origin formed about 3.8 billion years ago making it one of the oldest stones found on earth. Nuummite is also said to have strong metaphysical and spiritual healing properties.
| Category: | Mineral variety |
| Chemical Formula: | (Mg2)(Mg5)Si8O22(OH)2 |
| Magnesium Silicate Hydroxide | |
| Molecular Weight: | 780.82 gm |
| Composition: | Magnesium | 21.79 % | Mg | 36.13 % | MgO |
| Silicon | 28.78 % | Si | 61.56 % | SiO2 | |
| Hydrogen | 0.26 % | H | 2.31 % | H2O | |
| Oxygen | 49.18 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | Crystals rare, to 25 cm; as bladed aggregates of unterminated prismatic crystals. Commonly lamellar or fibrous, asbestiform. |
| Twinning: | None |
| Cleavage: | Perfect on {210}, Imperfect on {010} and {100} |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 5.5 – 6.0 |
| Density: | 2.85 – 3.57 (g/cm3) |
| Luminescence: | None |
| Color: | Gray, Brownish Gray, Yellowish Brown, Clove-Brown, Brownish Green, Emerald-Green; in thin section, Colorless to pale Green or Yellow |
| Transparency: | Opaque |
| Luster: | Vitreous, Pearly on cleavages |
| Refractive Index: | 1.598 – 1.697 Biaxial ( + ) |
| Birefringence: | 0.0170 – 0.0230 |
| Dispersion: | Weak to Moderate; r > v or r < v |
| Pleochroism: | When Fe-rich, moderate; X = clove-brown, yellowish brown, grayish brown; Y = clove-brown, brown-gray, brownish; Z = clove-brown to dark brown, grayish blue to green, lilac. |
| Anisotrophism: | Very Strong; Color in reflected light: |
