Diamond is a product of diamond finishing. Diamond is a hard and simple gem in the world. It is a natural crystal composed of carbon and has a cubic structure. Its composition is basically the same as that of our common coal, pencil lead and sugar. Carbon element crystallizes to form graphite (black) under high temperature and pressure, while it crystallizes into precious diamonds (colorless) in high temperature, huge high pressure and reducing environment (usually an anoxic environment). Diamond yield is very small, usually colorless crystals, with a high degree of refractive properties, can reflect the colorful luster. Diamonds can be used not only as jewelry, but also as advanced cutting and grinding materials in industry. The chemical properties of diamonds are very stable, and they are not easily soluble in acid and alkali at room temperature, and acid and alkali will not affect them. Diamonds are oleophilic and hydrophobic, so in the maintenance of diamond jewelry, it is emphasized to avoid placing diamonds in a heavy oil environment that affects the fire of diamond jewelry.