The hardness of gold is generally 2.5. Gold is divided into pure gold and alloy. Pure gold is soft, but alloy is hard. Alloy is a material with metallic characteristics, which is synthesized by two or more metals and nonmetals through a certain method.

Although gold has a strong luster, it is not very hard. You can see the tooth marks with your teeth, so it's easy to distinguish them.

Extended data:

According to different test methods, hardness test can be divided into static pressure method, scratch method, rebound method, microhardness, high temperature hardness and other methods.

Brinell hardness is expressed by HB[N(kgf/mm2)] (HBS\HBW). Brinell hardness method is often used to measure the hardness of annealed, normalized and quenched and tempered steel parts, as well as blanks or semi-finished products, such as cast iron, non-ferrous metals and low-alloy structural steel.

Rockwell hardness is divided into HRA, HRB, HRC and HRD, and their measuring range and application range are also different. In general production, the most used is HRC. Small indentation, can measure the hardness of thin and hard materials and finished products.

Vickers hardness is expressed as HV, which is used to measure extremely thin samples.

References:

Baidu encyclopedia-metal hardness