4 Miniature Teapots Cast Iron and Yixing Clay

These are such charming teapots. I believe them to be authentic Yixing clay. They are all in excellent shape except the reddish one has a tiny nick under the spout. The tallest one measures around 5 inches for perspective. I apologize, there is some sort of residue on the bottom of one of them, it is magnified dust I think 😕. I’m not sure of where the little cast iron one comes from.