sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Tan to off-white; Luster: Dull to vitreous; Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Tan to off-white
Luster: Dull to vitreous

Identified July 20, 2026More sedimentary →

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Physical properties

Hardness: 7 on Mohs scale; Color: Tan to off-white; Luster: Dull to vitreous; Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed through the weathering and erosion of larger igneous or metamorphic quartz-rich rocks, then rounded by water action in a river or coastal environment over thousands of years.

Uses & applications

Commonly used as construction aggregate, in landscaping, and in water filtration systems. Small pebbles like this are often part of gravel mixtures.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These rounded pebbles are often referred to as 'water-worn' stones because their shape is sculpted by the abrasive action of sand and water.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Commonly found in stream beds, beaches, and glacial deposits worldwide. This specimen is a typical piece of river or garden gravel.