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

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Hardness
7 on the Mohs scale
Color
Opaque white to translucent
Luster
Vitreous to greasy
Identified More mineral

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Physical properties

Hardness: 7 on the Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or as a late-stage mineral in igneous pegmatites. It is the most common variety of crystalline quartz.

Uses & applications

Used in glass manufacturing, as an abrasive, in decorative landscaping, and occasionally as a gemstone or in healing crystal collections.

Geological facts

The white color is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. It is found on every continent and is a major constituent of granite and sandstone.

Field identification & locations

Identify by its ability to scratch glass, its milky white color, and the lack of cleavage planes. It is often found as veins in host rock or as smooth pebbles in riverbeds.