俄罗斯科拉半岛铬云母玉的宝石学特征

在2010年,美国图桑的矿物宝石化石展销会上出现了一种新的玉石品种,其产自俄罗斯科拉半岛的铬云母玉。利用偏光显微镜、X射线粉末衍射仪、激光诱导离解光谱仪、红外光谱仪等测试方法对俄罗斯科拉半岛铬云母玉样品进行了分析与研究,初步确定其矿物组成、结构特征及宝石学性质。结果表明,该铬云母玉的主要矿物组成为铬云母、石英、长石,并含有少量的蓝晶石、十字石、高岭石、黄铁矿等;具有不等粒变晶结构和片麻状构造。与东陵石（即含铬云母的石英岩）的矿物组成和宝石学特征对比后,提出以铬云母的质量分数20%作为铬云母玉与东陵石的分类界限,其相应的宝石学和物理性质也可以对二者加以区分。

Gemmological Characteristics of Fuchsite Jade from Kola Peninsula,Russia

The fuchsite jade samples from Kola Peninsula,Russia appeared on Tuscon mineral,gemstone and fossil exhibition in 2010. The mineral components,structures and gemmo-logical characteristics of the fuchsite jade samples are studied by using the X-ray powder diffraction spectrometer （XRD）,laser-induced breakdown spectroscope （LIBS）,infrared spec-trometer （FTIR） as well as polarizing microscope. The results show that the fuchsite jade,which is of heterogranular crystalloblastic texture and gneissic structure,contains fuchsite,quartz,feldspar,and a small amount of cyanite,grenatite,kaolinite and pyrite. After thecomparison with aventurine quartz,the content of fuchsite with 20% is suggested as theboundary between fuchsite jade and aventurine quartz,and the corresponding gemmologicaland physical properties can be used to distinguish between fuchsite jade and aventurinequartz.