The cinnabar sold in Yonghe Palace is real. Real cinnabar jewelry reacts chemically with aluminum. Cinnabar will react chemically when it meets aluminum. It will be carved on aluminum products with vermilion, and after about 10 seconds, white hairs will "grow" on aluminum traces.
Cinnabar is a mineral and a natural mineral of mercury sulfide. It usually appears as a fine-grained lump, which is quite common in some southern regions such as Hunan and Chongqing. Cinnabar from crystal ore is also called soft ruby.