Natural gem: refers to the rare, beautiful and durable mineral single crystal produced in nature.

Natural jade refers to rare, beautiful and durable mineral aggregates and a few amorphous minerals produced in nature.

Crystals and diamonds are natural gems.

The formation of crystals is hydrothermal. In the process of magma crystallization, volatile substances containing ore, mainly water, gradually accumulate in it. In the late stage of magmatism, due to the development of structural fractures, the external pressure decreased. Volatile substances migrate upward within a certain period of time. As the temperature gradually decreases, these gaseous substances will be transformed into hot water solutions containing minerals when the critical temperature decreases. Minerals crystallize directly in these gas hydrothermal solutions, or recrystallize or account for them from surrounding rocks.

Diamonds are formed at high temperature and high pressure. Diamond deposits include kimberlite diamond deposits, K-Mg lamprophyre diamond deposits and placers.