具磷灰石假象绿松石的岩石矿物学及谱学特征

Study of the petrological mineralogy and spectroscopy of pseudomorphic turquoise with the structure of kietyoite

采用X射线粉晶衍射(XRD)、傅里叶变换红外光谱(FTIR)以及拉曼光谱等方法对安徽马鞍山具磷灰石假象的绿松石进行了研究。结果表明:其主要矿物组成为绿松石,保留了磷灰石六边形的形态特征。XRD测试的特征谱线d值为3.6745~3.6748(11ˉ1)、2.9008~2.9025(123)、3.4247~3.4293(210)、3.2709~3.2781(113)、6.1626~6.1781(011)和2.0130~2.0162(3ˉ01),与绿松石的标准衍射谱线基本一致。红外光谱测试分析表明:3510~3465cm-1间的谱带归属绿松石υ(OH)的伸缩振动,3300~3070cm-1间的谱带归属为绿松石υ(MFe,Cu-H2O)伸缩振动,1210~1012cm-1间的谱带归属为绿松石υ3(PO4)伸缩振动,在838cm-1附近的吸收谱带归属为绿松石δ(OH)弯曲振动,655~480cm-1间的谱带归属为绿松石υ4(PO4)弯曲振动。拉曼光谱测试分析表明:3466cm-1附近的尖锐拉曼谱峰归属于绿松石(OH)基团的伸缩振动所致,宽缓的拉曼谱峰3281cm-1和3078cm-1归属于绿松石中水合络离子的伸缩振动,798cm-1谱峰则是由于OH的弯曲振动所致。

X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, and Raman spectroscopy were used to study pseudomorphic turquoise from Maanshan City, Anhui province, China. The results indicate that the pseudomorphic turquoise mainly consists of turquoise minerals, which retain the hexagonal structure of kietyoite. The results of the XRD analysis showed that the main d values for pseudomorphic turquoise were 3.6745-3.6748（1T1）, 2.9008-2.9025（123）, 3.4247-3.4293（210）, 3.2709-3.2781（113）, 6.1626-6.1781（011）, and 2.0130-2.0162（~11）, which are in accordance with that of turquoise. The analysis of the FTIR spectrum showed that the ~equencies of the pseudomorphic turquoise bands were in the ranges 3510-3465 cm~ （u（OH） stretching vibration）, 3300-3070 cm~ （u（MFec^H20） stretching vibration）, 1210-1012 cm ~ （u3（PO4） stretching vibration）, around 838 cm ~ （6（OH） bending vibration）, and 655-480 cm ~ （u4（PO4） bending vibration）. The Raman spectroscopy showed that the sharp peak near 3466 cm~ was assigned to D（OH） stretching vibration, the bands ranging from 3281 to 3078 cm~ belong to D（MFecu-H20） stretching vibration, and the peak near 798 cm~ was classified as the 6（OH） bending vibration.