Milky Quartz

Physical Properties

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

Formation & Geological History

Formed through the crystallization of silica-rich hydrothermal solutions or magma. Milky quartz gets its characteristic white color from microscopic inclusions of fluids and gases trapped during crystal growth. Found in many geological environments from Precambrian to recent times.

Uses & Applications

Used in the production of glass, ceramics, and optical instruments. Also utilized in landscaping, as an abrasive, and sometimes in jewelry as cabochons. High-quality quartz is used in electronics for its piezoelectric properties.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. The white 'milkiness' is caused by tiny bubbles of gas or liquid that were trapped as the crystal formed millions of years ago, making it translucent rather than transparent.

Field Identification & Locations

Identify by its ability to scratch glass, lack of cleavage, and white opaque appearance. It is found globally in pegmatites, veins, and as a primary component of many igneous and metamorphic rocks. Collectors look for unique inclusions or crystal habits.

Identified on: 4/17/2026

Mode: Standard