ironstone

from The Collaborative International Dictionary of English v.0.48

Ironstone \I"ron*stone`\,
   1. n. A hard, earthy ore of iron.
      [1913 Webster]

   2. {ironstone china}.
      [PJC]

   {Clay ironstone}. See under {Clay}.

   {Ironstone china}, a hard white pottery, first made in
      England during the 18th century.
      [1913 Webster]