mineral

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with iron staining (yellow/brown); Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to translucent with iron staining (yellow/brown)
Luster: Vitreous to greasy

Identified May 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal activity where silica-rich hot fluids circulate through fractures in crustal rocks, precipitating quartz as they cool. This specimen appears to be a vein within a darker metamorphic or igneous host rock.

Uses & applications

Used as a primary source of silicon for electronics, in glassmaking, as an abrasive, and lower-quality specimens are used for construction aggregate or landscaping.

Geological facts

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

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage, and its typical white appearance against darker host rock. Often found in mountainous regions or near tectonic plate boundaries.

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