Shetaicui jade

“Shetaicui” mainly occurs north of Dashetai Town, Urad Front Banner, Bayannur City, Inner Mongolia. Tectonically, the study area is located on the northern margin of the North China Platform (Figure 1a), in the middle segment of the Zhaertai Mountain composite anticline, within the eastern part of the Langshan–Zhaertai fault–fold belt on the northern margin of the Langshan–Bayan Obo platform-margin depression. The Mesoproterozoic–Neoproterozoic Zhaertai Group is widely exposed in the area and consists of a low-grade metamorphic rock series derived from clastic rocks, carbonaceous shale, siltstone, and carbonate rocks modified by regional dynamothermal metamorphism.
Petrographic observations indicate that green “Shetaicui” is a fine-grained muscovite quartzite with a granoblastic texture and locally preserves a relict psammitic texture. Quartz is the major mineral, muscovite is a minor mineral, and zircon and rutile are accessory minerals. Petrographic and mineralogical evidence indicates that green “Shetaicui” records a three-stage formation process: sedimentary protolith formation, regional metamorphism, and jade formation during late fluid alteration.