Milky Quartz with Iron Staining

Physical Properties

Hardness: 7 on Mohs scale; Color: White to translucent with brown/yellow iron oxide staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal system); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Formed through the cooling of silica-rich magma or from hydrothermal veins. The iron staining occurs when the specimen is exposed to groundwater containing iron minerals, which seep into the surface fractures over time.

Uses & Applications

Used primarily in industrial applications such as glass making, abrasives, and electronics (due to piezoelectric properties). Lower quality specimens like this are used in landscaping, construction aggregate, or as basic collector pieces.

Geological Facts

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

Field Identification & Locations

Identify in the field by its ability to scratch glass, lack of cleavage, and characteristic 'blocky' fracture. It is ubiquitous worldwide, particularly in mountainous regions or riverbeds.

Identified on: 4/14/2026

Mode: Standard