In the later stage, the fluid that is rich in Ca-Mg-Fe components can replace early Jad I/Jad II, or it can coexist with Jad II, and metamorphism occurs to produce omphacite jade. According to the characteristics of cathodoluminescence, it can be speculated that the formation of jadeite undergoes three stages, and the formation of jadeite jade is mainly due to the crystallization (Jad I) of the early jadeite fluid, along with the second-stage fluid metasomatism/ crystallization (Jad II). The results showed that according to the composition, Guatemalan pyroxenic jadeite can be divided into three categories: jadeite jade, omphacite jade, and jadeite-omphacite jade. Seven varieties of green pyroxenic jadeite from Guatemala with greyish green, yellow green, brilliant green, blue green, dark green, black green and mottled green colors were investigated by combining the methods of XRD, Raman spectroscopy, cathodoluminescence, EPMA and m-XRF mapping. Guatemalan jadeite has a long history, and much Guatemalan jadeite can be found on the market today with a variety of colors and species diversity. The content of clinochlore provides a basis for grading the quality of the californite. Vesuvianite in the californite can be assigned to the P4/n space group, and the occurrence of clinochlore reflects the fact that the californite from Pakistan formed under medium-grade metamorphic conditions at temperatures of ~300–500 ☌. The actual color of californite that lacks clinochlore is due to the synergy of Cr3+, Fe3+ and Mn3+ crystal field transfers at the octahedral site Y3 as well as the Fe2+ → Fe3+ charge transfer in the vesuvianite. The Fe2+ → Fe3+ charge transfer also occurs in vesuvianite and partly influences the appearance of the californite. At sites where there is no clinochlore, Cr3+ in the octahedrally coordinated site Y3 of the vesuvianite is mainly responsible for the green tone of the californite, Fe3+ and Mn3+ at the Y3 site contribute mainly to the yellowish-green and reddish-brown colors, respectively. Octahedrally coordinated iron and chromium in the clinochlore reduce the transparency and contribute to the opaque green and yellowish-green colors of the californite. The transitional-type has properties that are intermediate between those of gem- and ordinary-quality californite. The ordinary-quality californite contains microcrystalline vesuvianite as well as clinochlore, and it has an opaque appearance. The gem-quality californite is composed of microcrystalline vesuvianite and has a translucent appearance. Based on the distribution of the clinochlore, the californite can be divided into three types. The results show that the californite is composed mainly of microcrystalline vesuvianite and smaller amounts of clinochlore. ![]() Four californite samples from Pakistan with yellowish-green, green and reddish-brown colors were investigated by combining the methods of μ-XRF mapping, XRD, Raman spectra, optical spectra, EPMA and XPS.
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