广西河池软玉的谱学和产地特征研究

广西河池市所产的软玉主要颜色是白色、青白色，少量墨绿色和黑色，是近两年才出现的品种，但是在市场上却占有不小份额，与其他产地相比，本区大部分软玉质地干，油脂光泽弱，且多数不透明，没有“水线”，常具有白色或者灰白色条带状包体以及褐色或者黑色“花瓣”状包体，市场上直接以“花瓣玉”进行销售。通过常规测试、拉曼光谱(Raman)、X光粉晶衍射(XRD)等测试，研究结果表明：广西河池软玉折射率为1.616～1.632，样品相对密度平均值为2.895，紫外荧光下样品均显示为惰性；样品的玉质部分和条带部分拉曼谱峰与标准软玉拉曼峰基本一致，主要峰值集中在225，370，676，1 029和3 677 cm-1，拉曼光谱和XRD测试表明玉石中的白色条带状包体的矿物组成依然为软玉，但是与周边玉石部分的软玉有不同的排列方式和颗粒大小，因此肉眼观察显示出条带状，并与正常玉石部分相比具有不同的颜色和透明度特征；经测试和计算发现研究样品结晶度平均值为0.963，大于新疆软玉样品的结晶度平均值0.843，与青海软玉结晶度0.96相近，反映出该区软玉的结晶程度较高，晶体颗粒相对较大的特征，预示其结晶过程冷却缓慢的特点，样品的结晶度好且同时颗粒排列比较不规则，造成玉石整体透明度下降。LIBS测试软玉中铍/硅强度比(I_Be/I_Si)显示新疆软玉为0.003～0.008，青海软玉为0，辽宁软玉为0.004～0.006，韩国软玉为0.1～0.16，俄罗斯软玉为0.03～0.05，广西河池软玉与青海软玉相同为0。

The Research on Spectroscopy and Locality Characteristics of the Nephrite Jade f rom Hechi,in Guangxi

The nephrite which has been found in Hechi ,Guangxi in the couple of years ,in various colors like white ,greenish white ,rarely dark green and black ,is gaining a growing popularity .Compared with those located in other places ,the Hechi nephrite presents a greasy luster which has a dry and mostly opaque texture without "water lines" ,the inclusions of which are band patterns in white or grayish white colors and dendritic patterns in brownish yellow and dark colors .That's why it is named"dendritic jade"in market .The samples were tested by standard gemological methods ,Raman spectroscopy ,X-ray diffraction (XRD) ,and other techniques .The research results show that the RI of them is from 1.616 to 1.632 ,an average hydrostatic S . G .2.895 ,inert under UV .The Raman spectra of jade part and white band are consistent with the standard Raman spectrum of nephrites .The main peaks are mainly 225 ,370 ,676 ,1029 and 3677 cm -1 .Despite the results of the Raman and XRD showing that the white bands are nephrites ,the band parts show different color and transparency with naked eyes because of different dis-play patterns and sizes of the grains in the bands .Through test and calculation ,the degree of crystallinity of research samples is 0.963 on average which is bigger than that of Xinjiang 0.843 on average and similar to that of Qinghai 0.96 on average .This means nephrites in this era crystallized well so as to make the mineral grains bigger ,which indicates that the characteristics of slow cooling crystallization process .Because the crystallinity of the samples is good and grains are more irregular at the same time ,the overall transparency of jade decreased .The value IBe/ISi of LIBS test on nephrites located in Xinjiang is 0.003~0.008 , Qinghai 0 ,Liaoning 0.004~0.006 ,Korea 0.1~0.16 ,Russia 0.03~0.05 ,while that of Hechi in Guangxi is 0 ,similar to that of Qinghai .