mineral

Milky Quartz Vein with Matrix

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with iron staining; Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

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

Identified April 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes where silica-rich hot fluids precipitate in fractures of existing rocks. Quartz can form in almost any geological age, typically associated with igneous intrusions or metabolic activity.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a semi-precious gemstone. Rough specimens are common in hobbyist collections.

Geological facts

Quartz is one of the most abundant minerals in the Earth's continental crust. Pure quartz is clear, but 'milky' quartz gains its opaque white appearance from tiny fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and glassy appearance. Often found in riverbeds, mountains, and as 'veins' protruding from darker host rocks.

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