mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: White to milky
Luster: Vitreous to greasy

Identified May 19, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary mineral in igneous rocks like granite. The milky appearance is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, electronics (due to piezoelectric properties), and widely as a semi-precious gemstone in tumbled form or jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of crystalline quartz found in nature. Historic specimens have been found in nearly every mountain range globally.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (hardness), its white opaque color, and lack of cleavage. Commonly found in riverbeds as tumbled pebbles or in hydrothermal vein outcroppings.