甘肃省武山县鸳鸯玉的地球化学和宝石学特征

对甘肃武山县鸳鸯镇鸳鸯玉的地球化学特征和宝石学特征进行的鉴定、分析和研究表明,鸳鸯玉是富镁铁的辉橄岩经岩浆期后多期热液的叠加蚀变(主要为蛇纹石化)形成的蛇纹岩;鸳鸯玉的主要矿物成分为蛇纹石,且多为叶蛇纹石,含有少量的透闪石、滑石、白云石,还有一定量的金属矿物,如磁铁矿、褐铁矿和水镍矿等。该玉石呈较深的灰绿色和墨绿色,质地细腻,可用于制作"夜光杯"和玉碗等工艺品。鸳鸯玉矿区交通方便,矿石开采成本低,是具有良好开发前景的玉石资源。

Geochemical and gemmological characteristics of Yuanyang Jade from Wushan County, Gansu Province

Geochemical and gemological characteristics of serpentine jade (Yuanyang Jade) samples from Yuanyang Town of Wushan County in Gansu Province were identified, analyzed and studied. The results show that Yuanyang Jade is serpentinite formed by superimposed alteration of Mg- and Fe-rich pyroxene-peridotite through post-magmatic multiphase hydrothermal activity, with serpentinization being the main mechanism of the alteration. The main mineral of Yuanyang Jade is serpentine, mostly lizardite. The minor minerals include tremolite, talc, dolomite and metallic minerals composed of magnetite, limonite and hydroniccite. The jade samples are dark green or blackish green in color and have fine texture, suitable for grinding into such handicrafts as jade cups for wining and jade bowls. There are transport facilities in the mining area of Yuanyang Jade, and the mining cost of the ore is low, thus constituting a good developing prospect for the jade.