Quartz Pebble

Physical Properties

Hardness: 7 (Mohs scale), Color: Milky white to translucent with iron staining (tan), Luster: Vitreous (glassy), Crystal Structure: Trigonal/Hexagonal (though rounded here), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65.

Formation & Geological History

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. This specific specimen has been further shaped and smoothed by water erosion (alluvial or glacial action), known as a stream pebble.

Uses & Applications

Quartz is used in the manufacturing of glass, electronics (oscillators), abrasives, and as decorative stone. Tumbled pebbles like this are often used in landscaping, aquariums, or as pocket stones.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Because of its hardness and chemical stability, it often survives long-distance transport in rivers and on beaches after other minerals have weathered away.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass and steel), lack of cleavage, and waxy to glassy appearance. It is extremely common in riverbeds, glacial tills, and beaches worldwide.

Identified on: 4/19/2026

Mode: Standard