河南省伏牛山“梅花玉”的宝石矿物学特征

Gemmological and Mineralogical Characteristic of “Meihua Jade” from Funiu Mountain,Henan Province

河南省伏牛山"梅花玉"是近期珠宝市场较流行的一个玉石品种,主体呈灰绿色至灰黑色,因形似梅花故称"梅花玉"。通过常规的宝石学测试、偏光显微镜、傅里叶红外光谱仪、电子探针、X射线单晶衍射仪等测试方法对河南省伏牛山"梅花玉"样品进行宝石矿物学特征的研究与分析。结果显示,河南省伏牛山"梅花玉"结构较疏松,蜡状光泽—弱玻璃光泽,玉石内部空隙被多种矿物充填形成各式各样的杏仁体,相对密度为2.82;河南省伏牛山"梅花玉"为一种灰绿色的粗面岩,杏仁状构造,其基质主要由钠长石、钾长石和阳起石组成,为玻基交织结构。斑晶主要由钠长石和钾长石组成,杏仁体主要由长石、石英、绿帘石、绿泥石、岩屑、方解石等矿物组成。

A kind of greyish-green to greyish-black ^Meihua jadew has been newly found inFuniu M ountain, Henan Province and it is called wMeihua jadew according to the surface patternlike plum blossom . In this paper, the gemmological and mineralogical characteristics ofwMeihua jadew samples were tested by using the conventional gemmological m ethods, polarizingm icroscope, Fourier transform infrared spectroscopy, electron probe analysis and X-raydiffraction. The results showed that the “ Meihua jade” from Funiu Mountain has loosestructure f waxy luster to weak vitreous luster. The internal voids with different mineralscalled amygdule. The relative density of precious stone is 2. 84_ The “ Meihua jade” from Fu-niu Mountain has amygdaloidal structure, and there are albite, K-feldspar and actinolite inthe matrix being hyalopilitic texture. Meanwhile, the tests of polarizing microscope and EPMAshowed that the phenocryst consists of albite with polysynthetic twin and K-feldsparwith simple twin. Most importantly, the mineral association of amygdule is complicated withfeldspar, quartz, epidote, chlorite, calcite, and detritus.