Gold

Physical Properties

Hardness: 2.5-3.0 Mohs; Color: Golden yellow to brassy; Luster: Metallic; Crystal Structure: Isometric (cubic); Cleavage: None; Specific Gravity: 19.3 (when pure)

Formation & Geological History

Formed primarily in hydrothermal quartz veins and as placer deposits where it has been eroded and transported by water. It is an elemental mineral found in the Earth's crust since its formation.

Uses & Applications

Extensively used in jewelry, coinage, gold bullion for investment, electronics (due to high conductivity and corrosion resistance), dentistry, and aerospace engineering.

Geological Facts

Gold is incredibly ductile; a single ounce can be stretched into a wire 50 miles long. It is a noble metal, meaning it does not oxidize or tarnish in air or water.

Field Identification & Locations

Identify in the field by its high density (heaviness), malleability (it bends rather than shatters), and yellow streak on a porcelain plate. Common locations include California, Witwatersrand, and Western Australia.

Identified on: 5/16/2026

Mode: Standard