Quartz Pebble

Silicon Dioxide (SiO2)

Rock Type: mineral

Quartz Pebble

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky white to light tan; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (though not visible in tumbled form); Cleavage: None, exhibits conchoidal fracture.

Formation & Geological History

Formed via crystallization from silica-rich hydrothermal fluids or within cooling magma. This specific specimen has been Rounded through fluvial (river) or coastal erosion processes, likely over several thousand years.

Uses & Applications

Used in construction, glassmaking, and as an abrasive. Polished pebbles are often used in landscaping, water features, and pocket stones for meditation.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. When crystals are found in caves or veins, they grow in distinct prisms, but most surface specimens are found as smooth pebbles like this one due to weathering.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass) and lack of cleavage planes. Found globally in riverbed gravels, beaches, and glacial deposits.

Identified on: 4/23/2026

Mode: Standard