和田玉、玛纳斯碧玉和岫岩老玉(透闪石玉)的X射线粉晶衍射特征

The X-ray powder diffraction feature of Hetian jade, Manasi green jade and Xiuyan old jade(tremolite jade)

软玉主要是指透闪石阳起石铁阳起石系列中的低铁富镁端员的隐晶矿物集合体 ,矿物的名称常以其Mg/ (Mg +Fe2 +)值来区分 ,即该比值大于 0 .9时为透闪石 (和田玉 ) ,比值为 0 .9～0 .5时为阳起石 (玛纳斯玉 )。对于产于新疆、辽宁 (岫岩老玉 )和青海的 17件软玉样品进行了X射线粉晶衍射分析 ,确定其主要矿物成分均为透闪石 ,杂质矿物很少 ,衍射峰位与FeO含量之间的关系不明显 。

Nephrite is used to be considered as aphanitic mineral aggregate which belongs to Fe\|poor and Mg\|rich member of actinolite\|tremolite series. Usually, the mineral names(tremolite and actinolite) are distinguished on the basis of Mg/(Mg+Fe 2+ ) ratio( 0.9 to be considered as the boundary). 17 samples of Hetian jade, Manasi green jade and Xiuyan old jade which come from Xinjiang, Liaoning and Qinghai have been investigated by means of XRD. The results show that all the samples are almost totally composed of tremolite, very few impurity can be found. No distinct relationship between peak positions and FeO contents can be determined. The diffusion of the peak shape probably indicates the variaton of crystallinity and grain size of the mineral composition.