mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to opaque
Luster: Vitreous to greasy

Identified July 9, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and pegmatites. The milky appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. They are found across all geological ages.

Uses & applications

Used in glass making, abrasives, electronics (piezoelectric properties), and as decorative gravel or landscaping stone. Also popular in jewelry as cabochons or tumbled stones.

Geological facts

Milky Quartz is one of the most common varieties of crystalline quartz on Earth. While it lacks the transparency of rock crystal, it is chemically the same material. High-quality quartz is essential for producing silicon chips.

Field identification & locations

Identified in the field by its hardness (will scratch glass), white color, and lack of cleavage. It is found globally, often appearing as veins in igneous and metamorphic rocks or as pebbles in stream beds.