Nuummite

Nuumit, also Nuummit, is a rare metamorphic rock composed mainly of the minerals gedrite and anthophyllite. The name is derived from the locality Nuuk in Greenland.

Rock

The base color is almost black and inclusions often colored shimmering; the rock is opaque. Besides the two amphiboles anthophyllite gedrite and pyrite, pyrrhotite and chalcopyrite occur as Nebengemengteile. The two amphiboles form a Zwillingslamellierung, which is caused by segregation ( exsolution ) in the solid state, and is distinguished in polished specimens through a yellowish- golden iridescence.

The original igneous rock succumbed after its formation in the Archean ( billion years ) before about 2.8 Ga geologically short time later - at about 2.7 Ga and 2.5 Ga - at least two metamorphic events, and today as ortho- amphibolite to address.

Occurrence

The rock was founded in 1810 for the first time in Greenland by the mineralogist KL Giesecke and scientifically collected first in 1905 and 1924 by OB Described Bøggild. Nuumit was found in Finland, the USA and the Commonwealth of Independent States.

Nuumit is rare and sought after because of its iridescence in gemstone dealers. It is marketed as a rough stone or tumbled stone in the trade. The rock is in demand by collectors and in esotericism.