Milky Quartz with Iron Staining

Physical Properties

Hardness: 7 on Mohs scale. Color: White/milky translucent with yellow-orange iron oxide staining. Luster: Vitreous to greasy. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & Geological History

Formed through the crystallization of magma or from hydrothermal veins. The milky appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. Iron oxide (limonite or hematite) staining occurs from weathering in surface environments.

Uses & Applications

Raw quartz is used in glassmaking, abrasives, and as a source of silicon for electronics. Specimens are popular for amateur collecting and metaphysical uses.

Geological Facts

Quartz is one of the most abundant minerals in Earth's crust. The 'milky' white color is due to millions of microscopic bubbles trapped inside the crystal as it grew millions of years ago.

Field Identification & Locations

Identify in the field by its hardness (it can scratch glass), lack of cleavage, and waxy/vitreous luster. Commonly found in gravel beds, stream deposits, and mountain outcrops globally.

Identified on: 5/14/2026

Mode: Standard