mineral

Rough quartz crystal, possibly smoky quartz

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Likely quartz based on its transparent-to-gray color, vitreous luster, and irregular crystalline faces. Hardness is 7 Mohs, lacks cleavage, has conchoidal fracture, and a specific gravity near 2.65; the small specimen appears partially weathered or matrix-coated.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, pegmatites, and igneous veins, commonly during Precambrian to younger geological events. The dark tint may reflect irradiation, inclusions, or iron staining rather than true smoky quartz.

Uses & applications

Quartz is used in glass, electronics, abrasives, countertops, and scientific instruments; attractive crystals are collected or cut as gemstones. This small rough piece has limited commercial value.

Geological facts

Quartz is one of Earth’s most abundant minerals and forms six-sided prismatic crystals when well developed. Definitive identification would benefit from testing hardness against glass and examining crystal faces.

Field identification & locations

Common worldwide, especially in Brazil, Madagascar, the United States, and alpine or hydrothermal vein environments. Look for glassy luster, no cleavage, and the ability to scratch ordinary glass.