四川石棉矿区软玉的岩石矿物学及扫描电镜研究

A petromineralogical and SEM microstructural analysis of nephrite in Sichuan Province

对四川石棉矿中的软玉进行了电子探针分析、X射线粉晶衍射分析、拉曼光谱分析及扫描电镜分析研究.结果表明其主要由透闪石组成,其中Mg/（Mg＋Fe）≥0.88-0.91,并呈现典型的透闪石晶体的拉曼谱图.计算的晶胞参数为：a0=0.984-0.985nm,b0=1.780-1.782nm,c0=0.527-0.528nm,β=106.13°-106.35°.四川软玉的猫眼效应由其内部显微纤维状的透闪石晶体而产生,透闪石纤维相互穿插绞合是玉石表现出高韧性和较强抗断裂性能的主要因素.

In this study, nephrite with chatoyancy from Sichuan province was studied by electron microprobe analysis (EPMA), X-ray powder diffraction analysis (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). Results indicate that the nephrite cat’s eye is composed mainly of ifber-shaped tremolite with Mg/(Mg+Fe)≥0.88–0.91, and unit cel parameters as folows: a0=0.984–0.985 nm, b0=1.780–1.782 nm, с0=0.527–0.528 nm, and β=106.13°–106.35°. The Raman spectra provide further proof of the mineral’s composition. The effect of the Sichuan nephrite cat’s eye is generated by microscopic ifbrous tremolite crystals. The ifber-shaped tremolite crystals are tightly arranged, which is the primary reason for the tenacity and fracture resistance of the nephrite cat’s eye.