clothes iron vs ironstone

clothes iron

noun
  • A hand-held device with a heated flat metal base used to smooth out wrinkles in clothes; an iron. 

ironstone

noun
  • Any ore of iron which is impure through the admixture of silica or clay. 

  • A type of vitreous pottery similar to stoneware 

How often have the words clothes iron and ironstone occurred in a corpus of books? (source: Google Ngram Viewer )