Gold

About it

Soft and very heavy; it dents under a pin and never tarnishes, while pyrite and chalcopyrite are hard and brittle. Found in quartz veins and placers worldwide, from the Klondike and California to Victoria, Australia.

Type

Mineral

Group

Native element, gold group

Formula

Au

Hardness (Mohs)

2.5–3

Specific gravity

15.5–19.3

Streak

golden yellow

Lustre

metallic

Crystal system

Isometric (cubic)

Colours

golden yellow, pale yellow when silver-rich

Transparency

opaque

Cleavage and fracture

none; hackly fracture, malleable

Typical values: real specimens vary. For more, see mindat.org.