mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: milky white to off-white; Luster: vitreous to greasy; Crystal Structure: Trigonal (often massive in pebbles); Cleavage: none; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: milky white to off-white
Luster: vitreous to greasy

Identified July 19, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: milky white to off-white; Luster: vitreous to greasy; Crystal Structure: Trigonal (often massive in pebbles); Cleavage: none; Specific Gravity: 2.65

Formation & geological history

Formed via crystallization from igneous melts or hydrothermal veins; subsequently eroded and tumbled by river or beach water action into a smooth, rounded shape.

Uses & applications

Commonly used in landscaping, as tumbling abrasive, or as a source for high-purity silica in industrial glass and electronics manufacturing.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These water-worn river stones are some of the most common geological finds worldwide due to quartz's extreme resistance to chemical and physical weathering.

Field identification & locations

Identify by its hardness (scratches glass), lack of visible grains like sandstone, and smooth, rounded surface. Found in stream beds, beaches, and glacial deposits.