mineral

Milky quartz with iron-oxide staining

Quartz (silicon dioxide, SiO₂), likely a translucent massive variety

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent, vitreous-to-waxy luster, conchoidal fracture, and no cleavage. The elongated internal bands may reflect quartz growth zoning or healed fractures, while the rough metallic-looking surface could be attached matrix or reflective fracture faces.

Identified August 19, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, pegmatites, or cavities in igneous and metamorphic rocks; individual growth ages vary from thousands to billions of years. This specimen appears naturally fractured and partly weathered, possibly later polished or worn.

Uses & applications

Common quartz is used in glass, ceramics, abrasives, foundry materials, and electronics; attractive milky quartz is collected and occasionally used ornamentally. It is generally not gemstone grade unless exceptionally clear or well formed.

Geological facts

Quartz is one of Earth’s most abundant minerals and forms six-sided crystals when space permits. Its lack of cleavage and conchoidal fracture are useful diagnostic features.

Field identification & locations

Test with a steel file or knife: quartz should resist scratching; it can scratch ordinary glass. Common localities include Brazil, Madagascar, the Alps, Arkansas, and many hydrothermal veins worldwide.