合成镁橄榄石的矿物学研究

Study on the Mineralogy of Synthetic Forsterite

人工合成的镁橄榄石具有优越的物理化学性能,使其在诸多领域得到应用,其中蓝紫色合成镁橄榄石被用作坦桑石的替代品进入珠宝市场,引起了珠宝行内外的广泛关注。本文通过X射线荧光光谱的定量分析和紫外-可见光吸收光谱的颜色成因分析,得出人工合成的蓝紫色镁橄榄石的主要成分为MgO和SiO2,并添加了致色金属元素钴和钒,组份相对简单,蓝紫色调的产生与钴离子有关;对合成橄榄石、天然橄榄石和坦桑石进行拉曼光谱(785nm)的定性分析,得到合成镁橄榄石与天然橄榄石都具有特征Si-O伸缩振动引起的拉曼位移820cm-1、853cm-1和961cm-1,而坦桑石中存在特征Si-O伸缩振动引起的拉曼位移866cm-1、923cm-1和1148cm-1,可有效鉴定该三种矿物。

Synthetic forsterites are widely used in many fields because of the super physical and chemical property. Among them the blue and purple ones were used as substitutes for zoisites in the gemstone market, which arose the common attentions in and around the gemstone industry. This paper was based on quantitative analyzing tested by XRF and coloration mechanism study tested by UV-VIS absorption spectrum, it was found that the main components of synthetic blue and purple forsterite were MgO and SiO2,and coloration element Co and V were added in it, the components were fewer; The turn-up of blue and purple color was connecting with Co ion; via qualitative analysis on synthetic forsterite, natural peridot and zoisite tested by Raman specter, it was found that Raman shifts 820cm^-1, 853cm^-1 and 961cm^-1 belonged to diagnostic stretching vibration of band Si-O existed in the Raman spectra of synthetic forsterite and peridot, whereas Raman shifts 866cm^-1 , 923cm^-1 and 1148cm^-1 belonged to diagnostic stretching vibration of band Si-O existed in the Raman spectra of zoisite. Owing to above testing methods, synthetic forsterite could be identified effectively with natural peridot and zoisite.