mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, semi-translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, semi-translucent
Luster: Vitreous to greasy

Identified May 29, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, semi-translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal solutions or as a cooling product in igneous and metamorphic rocks. This specific specimen appears water-worn, likely found in a riverbed or gravel deposit of Holocene age.

Uses & applications

Milky quartz is used as an abrasive, in glass manufacturing, as a gemstone (low-end jewelry), and as decorative gravel in landscaping.

Geological facts

Milky quartz gets its white color from tiny bubbles of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and translucent white appearance. Commonly found in riverbeds, gravel paths, and mountain trails worldwide.