How does this compare with weathering on other materials that the Hongshan used to carve with like nephrite and agate?
Bouncing off your reply David, this isn't limited solely to neolithic jade either. Bronzes from the Shang, Zhou and Han Dynasties can reach astronomical prices in big name auction houses like Christies and Sotheby's while not long ago, you could walk into a shop on Hollywood Street in Hong Kong and find a similar authentic piece for a mere fraction of the price at an auction house. This is primarily because most people believe that sentiment that David was talking about; that everything for sale there must be fake because everything old is rare and must be fake because of the low price. Judging the authenticity of ancient bronzes is also not nearly as difficult and controversial as jade. You can make a pretty sound initial judgment looking over the patina with a naked eye and a simple x-ray can confirm it.