mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with iron staining; Luster: Vitreous (glassy) to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to translucent with iron staining
Luster: Vitreous (glassy) to greasy

Identified April 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich hydrothermal fluids in veins or within igneous cooling environments. This specific specimen has been smoothed and rounded by water erosion (alluvial or beach transport).

Uses & applications

Used conceptually in glass making, electronics (piezoelectric properties), and as a landscape decorative stone. Large, clean specimens are used in lapidary work.

Geological facts

Milky quartz gets its white color from millions of tiny fluid inclusions of gas and/or liquid trapped during crystal growth. It is the most common variety of crystalline quartz.

Field identification & locations

Field identification: It will scratch glass, has no cleavage planes, and frequently shows iron-oxide (yellow/brown) staining in cracks. Commonly found in riverbeds, beaches, and mountain trails worldwide.