mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan with iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to tan with iron staining
Luster: Vitreous to greasy

Identified June 18, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to tan with iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent of igneous rocks like granite. This specimen likely comes from a hydrothermal quartz vein.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as decorative gravel or low-cost gemstone material.

Geological facts

The milky appearance is caused by tiny bubbles of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify by its hardness (will scratch glass), lack of cleavage, and translucent to opaque white color. Commonly found in riverbeds, mountains, and garden landscaping.