metamorphic
Nuummite
Nuummite (intergrowth of orthoamphiboles Anthophyllite and Gedrite, (Mg,Fe)7Si8O22(OH)2)
Hardness: 5.5-6.0; Color: Charcoal gray to black with iridescent flecks; Luster: Vitreous to sub-metallic; Crystal structure: Orthorhombic; Cleavage: Perfect; Specific gravity: 2.85-3.57.
- Hardness
- 5
- Color
- Charcoal gray to black with iridescent flecks
- Luster
- Vitreous to sub-metallic
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5.5-6.0; Color: Charcoal gray to black with iridescent flecks; Luster: Vitreous to sub-metallic; Crystal structure: Orthorhombic; Cleavage: Perfect; Specific gravity: 2.85-3.57.
Formation & geological history
Formed through high-grade regional metamorphism of igneous rocks approximately 3 billion years ago (Archean age). It is one of the oldest volcanic rocks known.
Uses & applications
Used primarily as a gemstone in necklaces, rings, and carvings (like hearts); also highly sought after by mineral collectors and the metaphysical community.
Geological facts
Commonly referred to as the 'Sorcerer's Stone,' it was discovered in 1982 near Nuuk, Greenland. Its iridescence is caused by internal reflections within the lamellar structure of the mineral intergrowth.
Field identification & locations
Identify by its distinctive metallic 'labradorescence' or 'schiller' effect, showing flecks of gold, blue, or red against a dark background. Found primarily in remote areas of Greenland, though similar material has been found in Finland.
More like this
