mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

Identified March 18, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through hydrothermal processes or within igneous pegmatites. It forms when silica-rich fluids cool and crystallize. Milky quartz is common in veins and can be found in rocks of almost any geological age.

Uses & applications

Used in the production of glass, ceramics, and sandpaper. Fine specimens are used in jewelry and lapidary art. In industry, high-purity quartz is used for silicon wafers in electronics.

Geological facts

The 'milky' appearance is caused by tiny inclusions 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 in the field by its hardness (it will scratch glass), lack of cleavage, and white/opaque color. It is commonly found in gravel, stream beds, and mountainous regions worldwide.