mineral

Quartz (Quartzite)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Tan to white (off-white); Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal system); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Tan to white (off-white)
Luster: Vitreous to greasy

Identified May 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Tan to white (off-white); Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal system); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich magma or precipitation from hydrothermal veins. This specific specimen appears to be a water-worn river pebble, shaped by erosion over thousands of years.

Uses & applications

Quartz is used extensively in glassmaking, ceramics, electronics (due to piezoelectric properties), and as an abrasive. Polished versions are used in jewelry and home decor.

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 often remains as pebbles while other minerals dissolve or break down.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), the lack of cleavage planes, and its waxy/glassy appearance. This specimen is a typical 'river rock' found in gravel pits, beaches, and stream beds worldwide.