Gold and Diamond

Physical Properties

Gold: Hardness 2.5–3.0, golden yellow color, metallic luster, isometric system, no cleavage, SG 19.3. Diamond: Hardness 10, colorless/white, adamantine luster, isometric system, perfect octahedral cleavage, SG 3.52.

Formation & Geological History

Gold often forms in hydrothermal quartz veins or as alluvial placer deposits. Diamonds form under extreme heat and pressure in the Earth's mantle (150–250km deep) and are brought to the surface via kimberlite pipes. Geological ages vary from millions to billions of years.

Uses & Applications

Primary use in jewelry, investment, electronics (gold's conductivity), and industrial cutting/drilling (diamond's hardness).

Geological Facts

Gold is so malleable that a single ounce can be beaten into a sheet 300 feet square. Diamonds are the hardest naturally occurring substance on Earth.

Field Identification & Locations

Identify gold by its high density and lack of tarnish; identify diamonds by their ability to scratch any other material and their high refractive index. Often found through mining operations in regions like South Africa, Russia, and Australia.

Identified on: 4/23/2026

Mode: Standard