What is the Mohs hardness of gold?

The Mohs hardness of gold is 2.5.

The Mohs scale measures scratch resistance by comparing a material with reference minerals, rather than measuring an absolute physical quantity. Gold’s position at 2.5 means it is softer than calcite, rated 3, and harder than gypsum, rated 2. Pure gold is therefore unusually easy to scratch, dent, bend, and shape.

This softness helps explain gold’s long history in jewelry, coinage, and decorative metalwork. Pure gold is often alloyed with metals such as copper, silver, palladium, or nickel to make objects more durable. Karat describes purity, not Mohs hardness: 24-karat gold is close to pure gold, while lower-karat alloys generally resist wear better, though their exact hardness depends on composition and treatment.

Gold’s softness is sometimes confused with its density or value. It is very dense—about 19.3 times as dense as water at room temperature—but density does not determine scratch resistance. The Mohs scale was devised by German mineralogist Friedrich Mohs and published in 1812.