Quartz (Milky or Iron-stained)

Physical Properties

Hardness: 7 (Mohs scale), Color: White, tan, or yellowish due to iron staining. Luster: Vitreous to waxy. Crystal Structure: Hexagonal/Trigonal. Cleavage: Indistinct/Conchoidal fracture. Specific Gravity: 2.65.

Formation & Geological History

Formed from cooling silica-rich magma or from hydrothermal veins. This specimen likely weathered out of a quartz vein and has been rounded by environmental exposure.

Uses & Applications

Used in glassmaking, abrasives, jewelry (as semi-precious stone), and as a structural component for electronics due to piezoelectric properties.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained varieties can transition into 'citrine' colorations if the iron content and heat history allow.

Field Identification & Locations

Identify in the field by its inability to be scratched by steel, its lack of cleavage, and the presence of conchoidal (glass-like) fractures. It is found globally in river beds, beaches, and mountain outcrops.

Identified on: 4/21/2026

Mode: Standard