Here are a few photos of a "new" (1991) speleothem from the Nullarbor called Stegamites (Webb 1991).
Quick characteristics of Stegamites. They look like ridges in floors or a vertical cave shield (They are always vertical.). Only known from the Nullarbor (7 caves to date) and possibly one cave in the Kimberley (Bill Humphreys pers. comms.). All Nullarbor stegamites are in black calite. The black material is as yet unknown. You can also see a few of the pics on The Virtual Cave which also has info on a number of cave formation types.
