田黄宝石的矿物学研究

我国名贵的田黄宝石,经X-射线衍射分析、红外光谱分析、差热分析及电子显微镜等研究,证实为一种罕见的珍珠石。田黄按宝石状态划分为三种:1.田黄冻,矿物成分主要为珍珠石,有时可见到一点伊利石。2.田黄石,是珍珠石与地开石成不同比例的混合物。3.银裹金,是纯白色半透明的地开石包裹着金黄色的冻状珍珠石。 这种宝石极为罕见难得,仅在我国寿山的坂田砾石层中偶然发现。文中探讨了寻找原生田黄的标志。

Mineralogy of Tianhuang Gem

A famous precious gem found in China and called tianhuang has been investigated by such means as X-ray diffraction, infrared spectroscopy, differential thermal analysis and electron microscopy. The results indicate that this mineral is a rare sort of nacrite and can be grouped into three kinds according to gemmology:1. Tianhuang gel: having nacrite as main composition, occasionally with a small amount of illite.2. Tianhuang stone., a mixture of nacrite and dickite in varying proportions.3. Gold coated with silver: golden-yellow nacrite wrapped in dickite which is pure white in colour and transparent to semitransparent.This type of gem is very rarely seen in the world and is only found in Bantian gravel bed in Shoushan, Fujian province. It is so valuable that its price is three times as high as that of gold. The indicators for primary tianhuang ore are also discussed in this paper.