2. Diamond, commonly known as "Jin Gangzuan", is a mineral made of carbon, which is an allotrope of carbon.

3. Emerald, known as the king of emeralds, is a very precious gem (May Birthstone) and one of the four precious gems (red, blue, emerald and diamond) recognized by the international jewelry industry. Because of its unique green color, unique charm and magical legend, it is deeply favored by westerners, and recently, it has been more and more loved by China people. Among many silicate minerals, emerald is the most attractive color, so it is loved.

4. Golden emeralds, also known as golden emeralds. The chemical composition is BeAl2O4, and the crystal is an orthorhombic oxide mineral. It ranks among the precious gems, including cat's eye, changeable stone, changeable stone cat's eye and gold emerald crystal.

Ruby refers to the red corundum, which is known as the "stone of love" and symbolizes the passion, beauty, eternity and firmness of love. Ruby is the birthstone of July. Ruby with different colors comes from different countries, but it also represents auspiciousness. Some ancient books think that ruby is "the most precious of the twelve gems created by God when he created everything."