now looking in my garage a used rear sprocket (70 teeth) that my given there are around 10 months and comes from a broken bike, I realized what had not been oxidized in cleaning the teeth I noticed that the tooth is like new, shiny as chrome which does not scratch with hss tip, it looks like hard chrome, it may be that his comes from a Japanese bike with belt 1 "1/2 pitch 14mm
sorry for picture distorted due to the perspective of the phone, there is no 1 / 10mm wear
