Gold

Gold is a chemical element with symbol Au (from Latin: aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element.

Properties

• Phase: Solid
• Density: 19.3 g/cm³
• Melting Point: 1337.33 K
• Boiling Point: 3243 K
• Extremely malleable and ductile
• Highly corrosion resistant and non-reactive
• Excellent electrical and thermal conductivity

Uses

• Coinage and bullion
• Jewelry and decorative gilding
• Electrical contacts and connectors
• Dentistry and medical devices
• Thin-film coatings for optics and aerospace

Extraction Process

Gold occurs as native metal in placer deposits and in quartz or sulfide ore veins. Placer gold is separated by gravity methods like panning and sluicing. Hard-rock ore is crushed, concentrated, and smelted, then refined by cupellation or chemical parting to remove silver and base-metal impurities.