Rock Identifier
Milky Quartz (Silicon Dioxide (SiO2)) — mineral
mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness
7 on Mohs scale
Color
Milky white to translucent
Luster
Vitreous to greasy
Identified More mineral
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Physical properties

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

Formation & geological history

Forms during the cooling of hydrothermal veins and pegmatites. It is the most common variety of crystalline quartz and is found in almost all geological environments worldwide.

Uses & applications

Used as a source of silica for glass manufacturing, as an abrasive, in electronics (piezoelectric properties), and widely as an ornamental stone or decorative gravel.

Geological facts

The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. It is the most common mineral in Earth's continental crust.

Field identification & locations

Identify by its hardness (it will easily scratch glass), its white color, and its lack of cleavage. Look for it in quartz veins, gravel pits, and mountain ranges.