mineral

Milky Quartz (Quartz Vein)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Opaque white to light gray
Luster: Vitreous (glassy) to greasy

Identified March 25, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids permeate cracks in existing host rocks (like the darker matrix shown). Typically found in metamorphic or igneous terrains ranging from Proterozoic to Cenozoic eras.

Uses & applications

Used industrially as an abrasive, in the manufacture of glass, ceramics, and electronics (quartz oscillators). Low-grade milky specimens are often used in landscaping and construction aggregate.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' appearance is caused by tiny fluid inclusions of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife and its lack of cleavage. It is extremely common globally, frequently found in riverbeds, mountains, and as 'float' in soil.