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

In the of pyroxeneadopted 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.