mineral

Smoky quartz

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Translucent gray-brown to champagne color with vitreous luster and irregular conchoidal fractures; Mohs hardness 7, specific gravity about 2.65, trigonal crystal structure, and no cleavage. The specimen appears to be a rough, fractured quartz crystal or chunk.

Identified October 15, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich fluids in veins, pegmatites, and cavities in igneous or metamorphic rocks. Smoky coloration is commonly caused by irradiation acting on trace aluminum; quartz ranges from Precambrian to geologically recent.

Uses & applications

Used for jewelry, carvings, ornamental objects, and mineral collecting; quartz is also important in glassmaking and electronics.

Geological facts

Quartz is one of Earth’s most abundant minerals, and its hardness makes it resistant to weathering.

Field identification & locations

Identify by its glassy luster, hardness, lack of cleavage, and conchoidal fracture; smoky quartz is common in Brazil, Madagascar, the Alps, and the western United States. A hand specimen of this size typically sells for about $5–$30, depending on clarity and crystal quality.