mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to yellowish-cream; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal system); Cleavage: None; Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Opaque white to yellowish-cream
Luster: Vitreous to greasy

Identified June 30, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Opaque white to yellowish-cream; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal system); Cleavage: None; Specific Gravity: 2.65.

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The milky appearance is caused by tiny inclusions of liquid or gas trapped during the crystal's growth. This specimen has been rounded by fluvial or glacial transport.

Uses & applications

Used in glassmaking, abrasives, gemstone carving, and as decorative landscaping stone. High-purity quartz is also essential in electronics.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was used by many cultures for tools and weapons before the widespread use of metal.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), lack of cleavage, and translucent to opaque white appearance. It is commonly found in stream beds, gravel pits, and beach deposits.