Milky Quartz Vein in Host Rock

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky white opaque quartz with tan/brown host rock; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed from hydrothermal solutions precipitating in fractures within host rocks at moderate to high temperatures. This specimen shows a vein of quartz that filled a void in a sedimentary or metamorphic matrix.

Uses & Applications

Used in glass making, abrasive manufacturing, electronics (due to piezoelectric properties), and as decorative landscaping stone or beginner collection specimens.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its color from tiny fluid inclusions of gas and/or liquid trapped during crystal growth.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass/steel), lack of cleavage, and white streak. Commonly found in mountainous regions or as pebbles in stream beds.

Identified on: 5/9/2026

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