mineral

Smoky Quartz with Feldspar

SiO2 (Quartz) with KAlSi3O8 (Potassium Feldspar)

AI-generated identification · may be incorrect

Hardness: 7 (Quartz) to 6 (Feldspar); Color: Translucent brown, tan, and white; Luster: Vitreous to dull; Crystal Structure: Trigonal/Monoclinic; Cleavage: None (Quartz) to Perfect at 90 deg (Feldspar).

Hardness: 7 (Quartz) to 6 (Feldspar)
Color: Translucent brown, tan, and white
Luster: Vitreous to dull

Identified June 19, 2026More mineral →

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Physical properties

Formation & geological history

Typically formed in pegmatites or hydrothermal veins where silicon-rich fluids crystallize. The smoky color is caused by natural irradiation of aluminum-bearing quartz.

Uses & applications

Used primarily for mineral collecting, lapidary and jewelry arts, and as an industrial source of silica.

Geological facts

Smoky quartz is the national gem of Scotland, where it is known as Cairngorm. Large crystals are often found in high-altitude alpine cavities.

Field identification & locations

Identify by its characteristic 'conchoidal' fracture on the glassy brown parts and the blocky cleavage of the lighter feldspar parts. Commonly found in granite-rich mountain ranges.