mineral

Milky Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Milky white to tan; Luster: Vitreous to waxy; Structure: Triganol/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to tan
Luster: Vitreous to waxy

Identified July 19, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to tan; Luster: Vitreous to waxy; Structure: Triganol/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Quartz forms in a wide variety of environments, primarily cooling from hydrothermal veins or as a component of igneous rocks. This specific specimen appears to be a river-worn or beach-tumbled pebble, rounded by aqueous erosion over long periods.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative stone or landscaping gravel. High-purity quartz is vital for silicon wafer production.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' appearance is caused by tiny fluid inclusions of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Commonly found in riverbeds, beaches, and gravel pits globally. It is a staple for beginner rockhounds due to its ubiquity and durability.