Gold Ore

Physical Properties

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

Formation & Geological History

Primary gold deposits form in hydrothermal veins precipitated from hot, aqueous fluids deep in the Earth's crust, often associated with quartz and pyrite. Secondary deposits (placers) form through erosion and river transport.

Uses & Applications

Primary use is in financial markets and jewelry. Also used extensively in electronics due to high conductivity and corrosion resistance, dentistry, and aerospace.

Geological Facts

Gold is incredibly malleable; a single ounce can be beaten into a sheet covering 100 square feet. It is one of the few elements that is chemically unreactive and does not tarnish.

Field Identification & Locations

Identify in the field by its high density and malleability; unlike pyrite (Fool's Gold), native gold will dent or deform under pressure rather than shatter. Look for high-contrast yellow streaks in quartz veins.

Identified on: 4/19/2026

Mode: Standard