Ever seen a piece of rock bend? Itacolumite is unique kind of sandstone that does when cut into thin strips. If a foot-long piece, a few centimeters thick, is supported at its ends it will gradually bend by its own weight. If it is then turned over it will straighten and bend in the opposite direction. Flakes a millimeter or two thick can be bent between the fingers and are said to give out a creaking sound.
The rock was first discovered in Mt. Itacolumi, hence named Itacolumite, in Minas Gerais, Brazil in 1822. It has since been found at a handful of places in India, France and the USA. However, the best samples still come from the Minas Gerais area.
