Organic gemstones. According to China Industrial Network, pearl is an ancient organic gem, which is mainly produced in mollusks such as pearl shellfish and mother-of-pearl. The calcium carbonate-containing mineral (aragonite) beads produced by endocrine function consist of a large number of tiny aragonite crystals; Rich in variety, different in shape and colorful; According to the research of geology and archaeology, there were pearls on the earth 200 million years ago.