Josh,

Check the HISTARCH archives for your answer to granite and ironstone, as this
has been discussed at length in the past. I just added my thoughts that
pottery industries were not as discriminate as archaeologists in marking ceramics
truthfully. They were appealing to a mass market, many of the buyers being
somewhat snobby about what they bought. There was a fashion to buy harder past
ceramics and even if the core of the pottery was soft the makers might have
marked it as granite to sell their products.

Ron