I think Ironstone is simply beautiful. First made in England in the early 1800's it was patented as the first ceramics made with feldspar. Exported to the US in the 1840's, it was marketed as the first white ironstone china in the US.
Martha Stewart did several comprehensive articles about ironstone in the 1990's, and the prices rose significantly. I stopped collecting then. Now, thankfully, the pieces are reasonably priced again. I like when the mineral discolors the white, and creates "crazing."
These are a few of the pieces I have found over the years.