Hardness
Hardness is one of the key indicators for identifying Hetian jade. The hardness of a mineral refers to its ability to resist penetration by other objects, which is a mechanical property. There are typically two ways to express hardness: (1) Relative hardness, also known as Mohs hardness, which measures scratch resistance. (2) Absolute hardness, also called indentation hardness, which is determined by the weight a mineral's surface can bear.
The Mohs hardness of Hetian jade is approximately 6.5, with slight variations among different types. Generally, green jade has a slightly higher hardness than white jade. In the jewelry industry, hardness is generally used as an important criterion for distinguishing between gemstones and jade. Gemstones usually have a hardness of above 7 on the Mohs scale, while jade typically ranges from 4 to 7 on the Mohs scale.