mineral

White Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Opaque white to milky white; Luster: Vitreous to dull when weathered; Crystal Structure: Trigonal (hexagonal system); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on the Mohs scale
Color: Opaque white to milky white
Luster: Vitreous to dull when weathered

Identified February 16, 2026More mineral →

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Physical properties

Formation & geological history

Formed from molten silica cooling in igneous rocks or precipitated from hydrothermal veins. This specific specimen became rounded through fluvial or marine erosion, where water transport smoothed its edges over long periods.

Uses & applications

Commonly used in landscaping (decorative garden stone), aquarium substrate, water filtration media, and as a raw material for glass manufacturing or high-purity silicon production.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specific 'milky' appearance is caused by tiny inclusions of gas or fluid trapped during the crystal's initial formation millions of years ago.

Field identification & locations

Identify by its ability to scratch glass and its lack of reaction to acid. In the field, it is easily found in riverbeds, beaches, and glacial deposits. For collectors, it is a staple of sedimentary rock identification exercises.