Milky Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous to greasy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & Geological History

Formed from the cooling of silica-rich hydrothermal solutions or magma. The cloudy white appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Can be found in veins or as a major constituent of igneous rocks like granite.

Uses & Applications

Used in glassmaking, construction aggregates, electronics (due to piezoelectric properties), and as decorative landscaping stones or ornamental carvings.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of quartz found in nature; it can often be an indicator of gold or other valuable minerals in hydrothermal vein deposits.

Field Identification & Locations

Identify in the field by its hardness (will easily scratch glass or steel), lacks cleavage (breaks in curved shards), and its white 'waxy' or 'oily' luster. It is found globally, particularly in mountainous regions and riverbeds.

Identified on: 4/29/2026

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