青田石“灯光冻”品种的宝石矿物学特征及其成因

Gemmological and Mineralogical Characteristics and Genesis of "Dengguangdong" in Qingtian Stone

采用X射线粉末衍射和电子顺磁共振等方法,对青田石中的珍贵品种"灯光冻"样品进行了研究。结果表明,"灯光冻"样品的矿物组成为叶蜡石,多型特征为2M型,含极少量的1TC型;其结构有序度高,化学成分表现为贫Al、富Si型,边缘部位具有石英化迹象。"灯光冻"样品中的Fe3+呈八面体占位,与Ti4+,Si-O--Al空穴心共同致色。"灯光冻"样品中的叶蜡石晶体呈不规则叶片状,大小较均一,呈弯曲片状集合体结构。

The ＂Dengguangdong＂ samples,a precious variety of Qingtian stone,are studied by using the X-ray powder diffraction（XRD） and electron paramagnanetic resonance（EPR） methods.The results show that the mineral component of the ＂Dengguangdong＂ samples is pyrophyllite.Its polymorphism is 2M,but containing rare 1TC,with a high degree-order structure and poor aluminum and rich silicon of the chemical composition.The edge of the sample is quartzification.Fe3＋ in the ＂Dengguangdong＂ samples is located in octahedron interstice.The ＂Dengguangdong＂ sample is colourated by Fe3＋,Ti4＋ and hole center of Si-O——Al.The pyrophyllite crystal in the sample is irregular bladed,uniform size and curved-platy aggregate structure.