Raw jade is hard to find. I have two pieces with donut shape, like the one in the post, one of them is imperial jade. There are techniques to diference serpentine from jade but not everybody knows it.

I write the posts myself from different sources that I have read, seen on TV and even experts with whom I have spoken so quoting them can be a bit difficult, especially because they are old things that I do not remember well hahaha, I even think that I took the mortuary mask out of a National Geographic book. Still I will try to find some sources for future post.

Thank you very much for reading, commenting and voting! :D