mineral

Smoky Quartz and Pyrite Cluster

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 7 (Quartz) and 6-6.5 (Pyrite). Color: Translucent grey to smoky brown with metallic brassy inclusions. Luster: Vitreous to metallic. Crystal structure: Hexagonal/Trigonal (Quartz) and Cubic (Pyrite). Cleavage: None/Conchoidal.

Hardness: 7 (Quartz) and 6-6
Luster: Vitreous to metallic

Identified April 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or pegmatites where silica-rich fluids cool and crystallize. The smoky color is caused by natural irradiation of aluminum impurities in the quartz over millions of years.

Uses & applications

Used primarily as decorative display specimens, in mineral collecting, and occasionally in metaphysical practices. High-quality quartz has historical uses in watchmaking and electronics.

Geological facts

Smoky quartz is the national gem of Scotland, where it is often referred to as 'Cairngorm.' The combination of cubic pyrite and smoky quartz makes for highly sought-after aesthetic contrast for collectors.

Field identification & locations

Identify in the field by the hexagonal prism shape of crystals and the smoky translucence. Found globally, but significant deposits exist in Brazil, the Swiss Alps, and the United States (Colorado and Arkansas).