mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Opaque white (milky)
Luster: Vitreous to greasy

Identified March 22, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms from the crystallization of molten magma or from hydrothermal veins. It can be found in a wide variety of geological environments ranging from igneous plutons to metamorphic zones and sedimentary deposits. Its age can range from billions of years to relatively modern formations.

Uses & applications

Used in the manufacturing of glass, ceramics, and abrasives. In electronics, synthetic quartz is used for its piezoelectric properties. Low-grade milky quartz is frequently used as landscaping stone, construction aggregate, or as a decorative material in home decor.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its characteristic white color from microscopic inclusions of gas or liquid trapped during the crystal's growth. It is often found associated with gold in hydrothermal vein deposits.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (H=5.5) and its lack of cleavage (it breaks like glass). It is ubiquitous globally, commonly found in gravel pits, riverbeds, and mountain outcrops. Collectors should look for well-defined crystal faces for higher value.