Found outside Baghdad, Iraq in 1936, the Baghdad Battery is a small clay jar containing an iron rod suspended in a copper cylinder which is soldered shut and sealed with asphalt.

The diluting mechanism of organic and inorganic diluents for porcelain clay containing montmorillonite slip have been explored by X-Ray Diffractometer and Transmission Electron Microscope.

A special clay containing iron and manganese oxides, used as a pigment for oil and watercolor painting.