河南淅川黑绿玉的矿物学研究

STUDY ON MINERALOGY OF HEILUYU JADE IN XICHUAN COUNTY, HENAN PROVINCE

河南省淅川黑绿玉质地细腻,颜色浓绿,为一种新型的玉石材料。本文对黑绿玉的矿物成分作了详细的研究,结果表明:黑绿玉的主要矿物成分为α型叶蛇纹石,含量大于90％,电镜下观察呈细条板状及叶片状,相互穿插,且有较大程度的定向性,具交织结构。其它矿物主要为磁铁矿、阳起石、方解石等,含量较少,主要分布于玉石的显微剪切理中。通过X光衍射、电子探针、红外吸收光谱及热分析等,对主要的蛇纹石矿物进行了种属确定,对其结构特征、结晶程度及成因等作了一些探讨,并对玉石(全岩)作了显微硬度测试。

The Heiluyu jade which emerges from Xichuan county, Henan Province is one kind of serpentine. It is a black green high quality jade. In this paper, the authors have studied the mineralogy of the Heiluyu jade in details and come to some conclusions, i. e, the jade is mainly made up of a-type antigorite (more than 90% of this jade). With the electron mi- croscope, we can see its thin banded and foliated shapes not only interlude with each oth- er, but also orientate and form an interlocking texture. Other minority minerals of this Jade are magnetite, actinolite and calcite etc. They are dispersed in the micro-shear joint, also. the main serpentine minerals have been determined by the X-ray diffraction, electron probe. infrared spectroscopic analysis and thermoanalytical technique. We have studied the serpentine from different means, such as structure characteristic, the degree of crys- tallization, and genesis. Finally, the microhardness of this jade (whole rock) is determined in this paper.