mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to creamy tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to creamy tan
Luster: Vitreous to waxy

Identified April 21, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to creamy tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from cooling magma or precipitation in hydrothermal veins. These specific smooth specimens were rounded by alluvial or marine erosion (water action). Age can range from millions to billions of years depending on the source vein.

Uses & applications

Used in landscaping, construction aggregate, glass making, and as pocket stones for collectors. High-purity quartz is used in electronics and optics.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These smooth 'river stones' are naturally tumbled by the energy of moving water over long periods.

Field identification & locations

Identify by its hardness (cannot be scratched by a steel knife) and lack of cleavage. Found globally in riverbeds, beaches, and gravel pits. Common for beginners to collect due to its durability and tactile smoothness.