There are only five kinds of precious stones, one is' diamond', which is produced in South Africa and of high quality. Second,' Ruby' is a high-quality producing area in Myanmar. Three' sapphires' are high-quality producing areas in Myanmar. Four. Emerald and high-quality Colombia. Five' golden emeralds', high-quality origin of Sri Lanka. The following is the ranking of gems: six emeralds, seven tourmalines, eight Ardisia/Garnets, nine crystals, ten spinels, eleven olivines, twelve beryls, thirteen topaz/topaz, fourteen zircons, fifteen moonstones, sixteen opals, seventeen diopsides and eighteen cordierite. Among them, gems such as; Tian Huangshi, Furong Stone and Shoushan Stone are not included.