mineral

Quartz Pebble (with Mica or Iron staining)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white with dark grey/black inclusions; Luster: Vitreous to dull (weathered); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white with dark grey/black inclusions
Luster: Vitreous to dull (weathered)

Identified March 30, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous pegmatites. This specific specimen has been chemically and mechanically weathered, likely in a riverbed or coastal environment, giving it a smooth, rounded 'river rock' shape.

Uses & applications

Quartz is used extensively in glassmaking, electronics (oscillators), and as an abrasive. Smooth pebbles are commonly used in landscaping, decorative aquariums, and rock tumbling.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The dark patches on this specimen are likely iron oxide staining or inclusions of dark minerals like biotite mica or schorl (black tourmaline) trapped during crystallization.

Field identification & locations

Identify in the field by its ability to scratch glass and its lack of cleavage. It is found globally in almost all geological environments. For collectors, look for high-transparency or unique mineral 'phantoms' inside the stone.

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