There are water marks in the blue and white jade. Is it hetian jade?

This phenomenon you mentioned is quite normal in Hetian jade. Technically, the straight waterline is called waterline, and the curved waterline is called jade tendon. Generally, when carving, the sculptor will get rid of the waterline and jade rib, but sometimes the position will be reserved when it is difficult to handle, but in this case, the price of the finished product will be greatly affected. Waterline and jade rib are the most common in Hetian jade, but sometimes they also appear in Hetian jade seed material.