mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 (Mohs scale); Color: Variegated grey/white/tan; Luster: Vitreous to waxy; Crystal Structure: Trigonal (often crypto-crystalline in worn pebbles); Cleavage: None; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Variegated grey/white/tan
Luster: Vitreous to waxy

Identified April 3, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Variegated grey/white/tan; Luster: Vitreous to waxy; Crystal Structure: Trigonal (often crypto-crystalline in worn pebbles); Cleavage: None; Specific Gravity: 2.65

Formation & geological history

Quartz pebbles generally form through the process of mechanical weathering and erosion. They originate from veins in igneous and metamorphic rocks, are transported by water systems (rivers/beaches) over long periods, and become smooth through abrasion.

Uses & applications

Small pebbles like this are used in construction aggregate, as landscaping material, in water filtration systems, and as tumbled decorative stones. Industrial grade quartz is used in glass and electronics.

Geological facts

Quartz is the second most abundant mineral in Earth's crust. Rounded pebbles are nature’s 'tumblers,' smoothed by thousands of miles of travel in riverbeds or thousands of years of tide action on beaches.

Field identification & locations

Identify in the field by its hardness (it should easily scratch glass) and lack of cleavage. Common in riverbeds, glacial deposits, and coastal beaches globally.