mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent white to tan; Luster: Vitreous (glassy) to greasy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Translucent white to tan
Luster: Vitreous (glassy) to greasy

Identified April 25, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent white to tan; Luster: Vitreous (glassy) to greasy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from cooling magma or hydrothermal veins. This specific specimen is a water-worn river pebble, likely eroded from a larger vein and smoothed by transport over thousands of years.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a component in construction concrete. Polished versions are used in landscaping and costume 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 often remains as rounded pebbles long after other minerals have decomposed.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and lack of cleavage (it breaks in curved, shell-like patterns). It is common in riverbeds, beaches, and gravel pits globally.