硬玉及相关辉石化学成份与翡翠玉种研究

A STUDY ON THE CHEMICAL COMPOSITION OF JADEITE, RELATIVE PYROXENE AND CLASSIFICATION OF JADE

198 7年国际新矿物和矿物命名委员会表决通过了“辉石的命名”方案。其中Na辉石和Ca Na辉石的命名仅考虑了硬玉—霓石—Ca Mg Fe辉石三元系 ,并且用Ca Mg Fe辉石组份80 %和 2 0 %的界限划分Ca Mg Fe辉石、绿辉石和硬玉。近 17年来硬玉和相关辉石的研究已经证实存在硬玉—霓石—Ca Mg Fe辉石—钠铬辉石四元系 ,只有用 5 0 %规则才能对四元系四面体矿物命名。在这个新的命名系统中保留了绿辉石名称 ,但它仅限于具P2空间群的绿辉石 ,把C2绿辉石分别归属硬玉和Ca Mg Fe辉石。翡翠玉种和硬玉的化学成份密切相关 ,据此划分了若干硬玉亚种。使用 5 0 %规则命名硬玉 。

In the 'nomenclature of pyroxene'adopted by CNMMN in 1987, the Na pyroxene and Ca-Na pyroxene were considered to be a ternary system of jadeite-aegirine-Ca-Me-Fe pyroxene. And the 80% and 20% of Ca-Mg-Fe pyroxene were used for the classification of Ca-Mg-Fe pyroxene, omphacite and jadeite. In recent decade or more, however, the study on jadeite and relative pyroxene has proved that there is a quaternary system of jadeite-aegiring-Ca-Mg-Fe pyroxene-kosmochlor. And the 50% regulation must be used for the nomenclature of minerals within the tetrahedron of quaternary system. In this new nomenclaure, the name omphacite is only used for the omphacite of P2 spacegroup, the varieties of C2 are divided into jadeite and Ca-Mg-Fe pyroxene. The jade variety is close relative to the chemical compostion of jadeite. A few subspecies of jadeite are classified in this paper. Using 50% regulation in this nomenclature, the traditional concept of jadeite wont be revised too much.