mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, milky, or translucent with iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, milky, or translucent with iron staining
Luster: Vitreous to greasy

Identified May 22, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 (Mohs scale); Color: White, milky, or translucent with iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins or as a constituent of igneous rocks. This pebble has been weathered and water-worn in a fluvial or coastal environment, rounding its edges over thousands of years.

Uses & applications

Used in glassmaking, electronics, abrasives, and as decorative garden stone or lapidary material. High-purity quartz is vital for silicon chips.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically very stable and resistant to physical weathering, which is why it often remains as pebbles long after softer rocks have eroded.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Common in riverbeds and beaches globally. Look for smooth, rounded textures and a waxy luster when wet.