Well I would beg to differ....tannin stains everything...porcel ain included...and the only way to get rid of it..is to soak the pot/cup..in bleach.or rinse in soda crystals......to prove my point..i will as of today...leave one of our cups,that we use to drink tea...i will only rinse it in hot water ..you, may be amazed as to how much tannin there will be on the porcelain after 1 week....as for your teapot....you may think its valuable....we however...do not....after a great deal of searching..we have,nt found anything that tells us its valuable....if it was as hold as you think....then i would expect it to be more worn...after all it is an every day object....this looks like it was made yesterday...