mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Translucent tan, beige, or off-white; Luster: Waxy to vitreous; Crystal system: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Translucent tan, beige, or off-white
Luster: Waxy to vitreous

Identified July 14, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Translucent tan, beige, or off-white; Luster: Waxy to vitreous; Crystal system: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous and metamorphic rocks. This specific specimen has been chemically and physically weathered into a smooth pebble shape through water transport in a river or stream environment.

Uses & applications

Used in landscaping, as aquarium gravel, in construction (aggregate), and for high-purity specimens, in electronics and glass manufacturing. Tumbled pieces are popular for amateur rock collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. River-worn pebbles like this one are often millions of years old and have traveled hundreds of miles, losing all sharp edges through constant abrasion.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Common in stream beds, beaches, and glacial deposits worldwide. Highly accessible for beginner collectors.