Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Rock Type: mineral

Quartz Pebble

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky white to translucent with orange/brown iron staining; Luster: Vitreous to waxy (when river-worn); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture.

Formation & Geological History

Formed through hydrothermal processes or within igneous rocks like granite. This specific specimen has been chemically weathered and physically eroded, likely by water action in a river or coastal environment, resulting in its smooth, rounded 'pebble' shape.

Uses & Applications

Quartz is used extensively in glassmaking, electronics (piezoelectric properties), abrasives, and as a common landscaping or decorative stone. High-quality varieties are used in jewelry.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Smooth white pebbles like this are often referred to as 'river rocks' and can be found almost everywhere on the planet due to their high resistance to weathering.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass) and its smooth, rounded surface. It is commonly found in stream beds, beaches, and glacial till. Collectors look for clarity or unique inclusions.

Identified on: 4/19/2026

Mode: Standard