Material (diamond, emerald, ruby and sapphire are four precious stones, which are expensive; Opal followed closely; Crystal, etc. Are all low-level. These are determined by its rarity, durability, aesthetics and public acceptance); Brand; Technology (for finished products); Jewelry in a broad sense also includes jade, which depends more on the processing technology and level; Where to buy it is also very important; Of course, antiques have their particularity.