mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to milky with yellow iron staining; Luster: Vitreous to waxy; Structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: White to milky with yellow iron staining
Luster: Vitreous to waxy

Identified July 2, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to milky with yellow iron staining; Luster: Vitreous to waxy; Structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Formation & geological history

Formed from cooling silica-rich hydrothermal fluids in veins or pegmatites. This specific specimen has been rounded and smoothed by fluvial or marine erosion over thousands of years.

Uses & applications

Used as a source of silica for glass manufacturing, as an abrasive, in landscaping, and occasionally as a low-cost decorative stone or worry stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' appearance is caused by tiny fluid inclusions trapped during the crystal's growth.

Field identification & locations

Identify by its hardness (will scratch glass) and lack of cleavage. Commonly found on beaches, in riverbeds, and as inclusions in metamorphic and igneous rocks worldwide.