玉器被埋入土中受到多种化学元素及温湿度的影响,每每显露出蚀变和染色等现象。古人对这种现象早已有所了解。收藏家根据对出土古玉的观察,总结经验,提出了“尸古”、“黑漆古”、“渠古”、“甄古”、“土古”等说法(明曹昭撰、王佐补《新增格古要论》卷六),以区别出土古玉发生的不同变化。随着时间的推移,这已成为说明古玉特征的名称。到了明代,由于出土玉器数量不足,远不能满足收藏家欣赏 Jade was buried in the soil by a variety of chemical elements and the impact of temperature and humidity, often revealing alteration and dyeing and so on. The ancients have long understood this phenomenon. Collectors based on the observation of the unearthed jade, summed up the experience, put forward the “dead ancient”, “black lacquer ancient”, “ancient”, “ancient”, “ancient” (Ming Cao Zhaoxuan, Wang Zuobuxu “new grid to be on” Volume VI), to distinguish the different changes in unearthed jade. Over time, this has become the name of the jade characterization. To the Ming Dynasty, due to the lack of unearthed jade, far from satisfying collectors appreciate