mineral

Quartz (Milky Quartz vein fragment)

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 from silica-rich hydrothermal fluids cooling in rock fractures (veins) or as a primary constituent in igneous rocks like granite. These specimens can range from millions to billions of years old depending on the host rock formation.

Uses & applications

Used industrially in glass making, ceramics, and as an abrasive. Also used as construction aggregate, in electronics as oscillators (piezoelectric properties), and for jewelry or landscaping.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but 'milky quartz' gets its white color from tiny fluid or gas inclusions trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (will scratch glass/steel), lack of cleavage, and white/opaque appearance. It is found globally in riverbeds, mountains, and gardens. Often used as decorative gravel in driveways or landscaping as seen in the background of the image.

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