摘要
为了探究一种商业上被称为“美国紫云母”的紫色玉石与相似宝玉石的区别,以及其白色矿物与紫色矿物主体的成分差异,采用宝石显微镜、折射仪、紫外-可见近红外光谱仪、傅里叶变换红外光谱仪、电子探针和X射线粉末衍射仪等测试仪器对“美国紫云母”样品进行检测与分析。结果表明,“美国紫云母”样品的红外光谱可见结晶水引起的3382、3114、1634 cm-1附近的吸收峰,以及[PO 4]3-振动所致的1025、594、469 cm-1附近的吸收峰,非云母的特征吸收,位于1511 cm-1处的弱吸收峰为双酚A型环氧树脂的弯曲振动引起;X射线衍射数据显示,“美国紫云母”样品为成分较纯的红磷铁矿(又名斜红磷铁矿);电子探针测试结果符合变红磷铁矿化学式FePO 4·2H 2 O。紫外-可见光谱可见424 nm附近的强吸收峰,以及539 nm附近和751 nm附近的宽吸收带,证明“美国紫云母”样品为经过充填、未经染色处理的变红磷铁矿。“美国紫云母”样品中白色部分与紫色部分在正交偏光显微镜下无明显差异,拉曼光谱基本吻合,扫描电子显微镜结果显示,白色部分和紫色部分的组成元素相同,仅致密度有所差异,说明样品紫色与白色部分为同种矿物,推测其颜色差异可能归因于致密度的不同。
To analyze the difference between a kind of purple jade called“American mica jade”recently appeared in Anhui market and its similar gemstones,as well as the component of the white and purple minerals in the purple jade,the gem microscope,refractometer,UV-Vis,FTIR,EPMA and XRD were used in this paper.The results showed that the infrared spectra of the purple jade samples have 3382、3114、1634 cm-1 peaks caused by crystal water,and peaks near 1025、594、469 cm-1 caused by[PO 4]3-which are not characteristic absorptions of mica.The peak at 1511 cm-1 is caused by the bending vibration of bisphenol A epoxy resin.X-ray diffraction data showed that the main constituent mineral of the purple jade sample is pure phosphosiderite(also known as chinostrengite).Electron probe assay showed that the chemical formula of purple jade samples is FeSO 4·2H 2 O.The strong absorption peak near 434 nm,and wide absorption peak near 539 nm and 751 nm can be seen in the UV spectra.It was proved that the the purple jade sample has been filled but not dyed.The Raman spectra of the purple and white minerals in the purple jade sample were basically consistent.The SEM result showed that the main elements of the purple and white minerals are the same,only the densities are different.Therefore,the colour difference may be attributed to different density.
作者
于露
李玏
曹素巧
王枫
郭连巧
YU Lu;LI Le;CAO Suqiao;WANG Feng;GUO Lianqiao(Anhui Geological Experiment Institute/Hefei Mineral Resources Supervision&Testing Center of the Ministry of Land&Resources of the P.R.C,Hefei 230001,China;Nanjing Institute of Product Quality Inspection,Nanjing 210028,China)
出处
《宝石和宝石学杂志》
CAS
2019年第6期40-49,共10页
Journal of Gems & Gemmology