Acta Petrologica et Mineralogica

The newly discovered high-quality green jadeite in Guatemala is comparable to the high-end green jadeite from Myanmar, gradually becoming an important source of high-quality green jadeite jewelry materials in the domestic jewelry market. However, research on its petromineralogy and typomorphic characteristics remains relatively weak. This study selects a large number of Guatemalan high-quality green jadeite materials and jewelry that have appeared in the Chinese market as research subjects. Through microscopic observation, laser Raman spectroscopy, EMPA, and other testing methods, a systematic analysis of their mineral assemblages and compositional characteristics was conducted. The research findings indicate that the high-quality Guatemalan green "Mayan Green" jadeite materials appearing in the market are primarily composed of omphacite minerals, with secondary minerals including phlogopite, phengite, zoisite. Omphacite can be classified into three different formation stages, Omp-Ⅰ, II, and III, based on its mineral assemblages and their interrelationships. Among them, the high-quality Guatemalan green jadeite jewelry are mainly composed of omphacite formed in the Omp-Ⅲ stage, characterized by relatively low Mg (average 7.59%) and Fe (average 1.57%) contents, relatively high Cr content (average 0.24%), and a jadeite component X_jd>0.5 (average 0.53). Existing research indicates that the jadeites in different segments of the Motagua Fault System in Guatemala possess distinct mineral assemblages. However, the high-quality green jadeite jewellerys studied in this paper exhibit a relatively uniform mineral composition in the domestic market, primarily composed of pure omphacite. They may contain two specific metal mineral inclusions, chalcocite and nickeline. The endmember composition and mineralogical characteristics show significant differences compared to other sources of high-quality green jadeite, enabling effective differentiation between high-quality Guatemalan green jadeite, traditional Myanmar green jadeite, and high-quality green jadeite from other origins by providing essential reference characteristics in petrology and mineralogy.

jadeite; omphacite; petromineralogy; typomorphic characteristics; Guatemala