Diamond refers to polished diamond, which is a natural mineral and the original stone of diamond. Simply put, diamond is a simple crystal composed of carbon element formed under high pressure and high temperature conditions in the deep part of the earth.

Diamonds are beautiful and rare. They are symbols of love and loyalty, representing eternal love. Diamonds have the highest hardness and high brittleness among natural minerals, so they will break when they collide with each other. From the ancient Greek agonist, which means hard and inviolable substance, it is recognized as the king of gems.

Classification of gems:

1. High-grade gems: including 7 kinds of diamonds, rubies, sapphires, emeralds, golden-green cat's eyes, variable stones and high-grade pearls. Among them, diamonds, rubies, sapphires and emeralds are called gems by western countries. Diamonds are the king of jewels.

2. Intermediate gemstones: including aquamarine, tourmaline, zircon, spinel, etc. , more common. Grade pearls, jadeite and opal are also classified as middle-grade gems.

3. Low-grade gems: including turquoise, topaz, amethyst, olivine, topaz, sapphire and other varieties.