Quartz (Vein Quartz)

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky white with orange-brown iron staining; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal (though massive/microcrystalline in this specimen); Specific gravity: 2.65.

Formation & Geological History

Formed from hydrothermal solutions cooling in rock fractures (veins). This specific specimen appears to be a water-worn or river-tumbled pebble with secondary iron oxide staining (limonite or hematite) on the surface.

Uses & Applications

Quartz is used in glassmaking, electronics (piezoelectric properties), and as an abrasive. Polished river stones of this type are used for landscaping, interior design, and aquarium decoration.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. The yellow-brown streaks seen here are often called 'iron staining' and occur when water carrying iron minerals seeps into micro-cracks in the silica.

Field Identification & Locations

Identify in the field by its inability to be scratched by a steel knife (H=7) and its conchoidal (shell-like) fracture. Commonly found in riverbeds, glacial tills, and near hydrothermal outcrops.

Identified on: 4/27/2026

Mode: Standard