mineral

Quartz (Microcrystalline variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless to milky grey/brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless to milky grey/brown
Luster: Vitreous to waxy

Identified April 7, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Colorless to milky grey/brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich hydrothermal fluids or within sedimentary nodules. This specimen appears to be a weathered water-worn pebble or a fragment of a larger quartz vein/geode.

Uses & applications

Common quartz is used in construction as aggregate, in glassmaking, and in electronics as a piezoelectric material. Lower grade specimens like this are primarily of value to hobbyists and beginners.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically and physically resistant to weathering, which is why it often survives as smooth pebbles in riverbeds and on beaches.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (7 hardness) and its characteristic glass-like, shell-shaped (conchoidal) fracture surface. Found globally in almost all geological environments.

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