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

Milky Quartz

Silicon Dioxide (SiO2)

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

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

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Physical properties

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

Formation & geological history

Formed from silica-rich hydrothermal solutions or as one of the last minerals to crystallize from cooling magma in igneous rocks; found in veins and pegmatites across all geological ages.

Uses & applications

Used in glass manufacturing, as an abrasive, in electronics for its piezoelectric properties, in construction as aggregate, and in landscaping or jewelry as beads and tumbled stones.

Geological facts

The milky white appearance is caused by tiny liquid or gas bubbles trapped within the crystal during its formation. It is the most common variety of crystalline quartz found on Earth.

Field identification & locations

Identify by its hardness (will scratch glass), lack of cleavage, and white waxy look. They are frequently found in riverbeds, mountains, and as garden stones. It is an excellent beginner specimen for rockhounds.