mineral

Polished quartz crystal with iron-oxide inclusions

Quartz, silicon dioxide (SiO₂), likely included with hematite/goethite or iron staining

AI-generated identification · may be incorrect

Hardness 7 Mohs; transparent to translucent, colorless to pale gray with reddish-brown inclusions; vitreous luster and conchoidal fracture. The oval cabochon is polished and lacks visible cleavage; quartz is trigonal and has specific gravity about 2.65.

Identified September 9, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids or pegmatites, while iron oxides form later inclusions or stains along fractures. Quartz deposits range from Precambrian to modern geological ages.

Uses & applications

Used as a gemstone cabochon, ornamental stone, and collector specimen; quartz is also important in glassmaking, electronics, abrasives, and engineered stone.

Geological facts

The reddish-brown areas are commonly hematite, limonite, or goethite rather than a separate red mineral. A polished surface can make internal fractures and inclusions appear layered or dendritic.

Field identification & locations

Identify by its glassy luster, strong scratch resistance, and lack of cleavage; it should scratch ordinary glass but not be scratched by steel. Common sources include Brazil, Madagascar, India, and quartz-bearing hydrothermal veins.