Translucent, bright single crystal with sharp, well-defined faces and of considerable size, showing a prismatic habit with marked longitudinal striations. The luster is vitreous to silky.
This species, belonging to the inosilicate subclass, is rare, especially in crystals of this size and quality.
The Koksha Valley is a mountainous region historically known for its gemstone deposits. This valley forms part of the classical Sar-e-Sang area, one of the most renowned localities in the world for its lazurites (lapis lazuli), exploited since antiquity.
From a geological point of view, the area corresponds to high-grade metamorphic units, with marbles and gneisses in which mineralizations associated with metasomatic and metamorphic processes develop. The paragenesis is characteristic, with the presence of lapis lazuli (a rock composed predominantly of Lazurite), together with Pyrite, Calcite, and other associated silicates, in a context that has given rise to some of the most historically well-known gem materials.
Koksha pegmatite field, Koksha Valley, Khash & Kuran Wa Munjan Districts, Badakhshan Province Afghanistan (±2004)
Specimen size: 3.4 × 3.1 × 1.8 cm = 1.34” × 1.22” × 0.71”
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