mineral

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Variable (mostly white/opaque in this specimen); Luster: Vitreous to greasy; Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Variable (mostly white/opaque in this specimen)
Luster: Vitreous to greasy

Identified March 30, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms in all types of environments but most commonly crystallizes from cooling magma or hydrothermal veins. This specimen appears to be of hydrothermal origin, likely millions of years old, often found in pegmatites or sedimentary deposits as eroded pebbles.

Uses & applications

Used widely in glassmaking, abrasives, and as a component in construction (sand). Quality crystals are used in electronics for their piezoelectric properties and as semi-precious gemstones in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it is the primary component of most beach sand and survives long after surrounding rocks have eroded.

Field identification & locations

Identify in the field by its inability to be scratched by a steel pocket knife and its characteristic glassy, shell-like (conchoidal) fracture surfaces. Commonly found in riverbeds, mountains, and gravel pits worldwide.

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