Quartz Vein in Host Rock

Physical Properties

Hardness: 7 (Mohs); Color: Milky tan to white quartz paired with greyish-brown host rock; Luster: Vitreous to greasy; Crystal structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture).

Formation & Geological History

Formed through hydrothermal processes where mineral-rich hot water flows through fractures in pre-existing rocks, depositing silica that cools and crystallizes into quartz. Common in orogenic belts and tectonic zones.

Uses & Applications

Quartz is used in glassmaking, electronics (piezoelectric properties), and as an abrasive. Specimens like this are primarily of educational or local geological interest.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Vein quartz often acts as a 'host' for precious metals like gold in certain geological environments.

Field Identification & Locations

Identify by the contrast in hardness between the harder quartz vein and the surrounding rock. It will easily scratch glass. Found commonly in creek beds, mountain trails, and construction sites.

Identified on: 5/4/2026

Mode: Standard