安徽马鞍山宝石级白磷铁矿的振动光谱表征

Vibration Spectrum Characteristic of Gem-Grade Tinticite from Ma’anshan,Anhui Province

安徽省马鞍山绿松石矿区发现了一类与绿松石伴生且外观与其相似的宝石矿物材料——白磷铁矿,呈土状-蜡状光泽、不透明、结构细腻、易吸水,一般为浅黄绿色至浅绿黄色。与其他绿松石相比,其硬度较低。以此类宝石矿物材料为研究对象,采用宝石显微镜、折射仪、傅里叶变换红外光谱仪、激光拉曼光谱仪、X射线粉末衍射仪、紫外-可见分光光度计等对其矿物组成进行确定,并获得其谱学特征。结果表明,该样品的主要矿物组成为白磷铁矿,并含有少量的绿松石和黄钾铁矾。白磷铁矿样品的红外光谱主要表现为由OH的伸缩振动引起的3390 cm^(-1)附近的特征峰、结晶水弯曲振动所致的1630 cm^(-1)以及PO_(4)^(3-)伸缩振动所致的1129、1110、1064、1019、961、877、760 cm^(-1)处特征峰。激光拉曼光谱检测到白磷铁矿样品的拉曼位移1091、1018、556 cm^(-1)是由PO_(4)^(3-)伸缩振动引起。因此,实验室可根据主要矿物组成、红外光谱、激光激光拉曼光谱等特征,对其进行快速有效的无损鉴定。

Tinticite,which is associated with and has a similar appearance of turquoise was found in the turquoise mining area in Ma’anshan,Anhui Province,China.It has earthy to waxy luster,opaque,fine structure,and easy to absorb water.Generally it has light yellowish green to greenish yellow colour.Compared with turquoise,it has lower hardness with similar structure.Gem microscope,refractometer,Fourier transform infrared spectrometer,Raman spectrometer,X-ray powder diffractometer and UV-Visible spectrophotometer were used to identify the mineral components and spectral characteristics of tinticite.The results show that its main mineral compoment is tinticite with a small amount of turquoise and jarosite,which has rarely been reported in previous studies.The infrared spectrum of tinticite is mainly represented by the characteristic peak near 3390 cm^(-1) caused by the stretching vibration of OH,the 1630 cm^(-1) peak caused by the bending vibration of crystal water,and 1129,1110,1064,1019,961,877,760 cm^(-1) characteristic peaks caused by stretching vibration of PO_(4)^(3-).Raman spectrum analysis detect that the Raman shifts at 1091,1018 cm^(-1) and 556 cm^(-1) of tinticite are caused by the stretching vibration of PO_(4)^(3-).The samples can be identified quickly and effectively in the laboratory according to their main mineral component characteristics,infrared absorption spectrum,Raman spectrum characteristics,etc.