Kashrut of Porcelain Tableware

This question concerns the use of porcelain dishes. Porcelain ware contains finely ground bone powder which gives the shine to the vessel. The word porcelain is indicative of the treif word itself. I thought that only ceramic was acceptable whereas I have seen people use Royal Doulton porcelain. Are porcelain dishes kosher or not??

They are Kosher and should be Toveled without a Bracha. esw