Jewelry: In a broad sense, all beautiful ornaments are jewelry. For example, the concept of jewelry in primitive society is round stones or the teeth of prey. In a narrow sense, it mainly includes: gems (single crystal structure, beautiful and rare stones, diamonds, rubies, emeralds, crystals, etc. ), jade (a collection of various minerals, jadeite, Hetian jade, Xiuyu jade, Nanyang jade, lantian jade, etc. ), precious metals (gold, silver, platinum, palladium) and rare organic substances (ivory, pearls, etc.). ). But formally speaking, jade is also a gem.