gems, jade, fei cui, pyroxene jade, jadeite, fei cui, Indonesia, Sulawesi

Jade is considered a precious rock or gemstone. Jadeite jade is abundant in high-pressure metamorphic garnet–jadeite–quartz rock found in the Bantimala Complex of South Sulawesi, Indonesia. This study presents the petrography, mineral chemistry, and metamorphic evolution of such rock. It primarily consists of jadeite, garnet, quartz, phengite, and epidote, with subordinate glaucophane and rutile. Fine-grained epidote, phengite, and albite, with or without garnet, occur sporadically and are likely pseudomorphs after lawsonite. Allanite, a rare-earth element-bearing mineral, is abundant and typically found in the core of epidote grains, giving this rock the highest REE pattern among high-pressure metamorphic rocks from the region. During metamorphism, the rock existed within the phengite + jadeite + lawsonite + katophorite/winchite + quartz stability field during the prograde stage. NCKFASHO pseudosection modeling and garnet–phengite thermometry indicate peak P–T conditions of 2.2–2.5 GPa and 500–540 °C, followed by retrogression in the stability field of epidote, phengite, jadeite, amphibole, and albite. The garnet–jadeite–quartz rock of South Sulawesi holds significance for both tectonic interpretation and its economic value as a gemstone and rare-earth-element-bearing rock. Further study is needed to understand its distribution and occurrence.