1, diamond

As a gem, it must have three elements: beauty, durability and rarity. Diamond is the only gem with the highest hardness, strong refractive index and high dispersion, which is superior to other gem varieties. Since ancient times, diamonds have been regarded as a symbol of power, majesty, status and wealth by human beings.

2. Ruby

Refers to red corundum, which is a kind of corundum, and its main component is alumina (Al? o？ )。 Ruby is one of the precious varieties in jewelry. Ruby is brightly colored. Under the illumination of light source, it can reflect beautiful six-ray starlight, commonly known as six lines. This is due to the special crystal structure of ruby and its unique optical phenomenon.

3.sapphire

Sapphire belongs to corundum group minerals and has a tripartite crystal system. All kinds of gems except ruby are called sapphires, among which sapphire and cornflower are the best, thick but not black. When polished on a curved surface, the inside is rich in three packages of crystals arranged parallel to the bottom, which can produce beautiful six-ray light.

4. Emerald

Emerald is the king of emeralds, and its color is very attractive. Whether it is cloudy or sunny, its surface can emit soft and strong light under artificial light or natural light. According to the special optical effects, emeralds can be divided into emeralds, cat's eye emeralds, star emeralds and Darbiz emeralds.