I am trying to find a gypsum mineral that's light brownish in color, glossy and transforms into a white/brownish powder when crushed. Unlike the gypsum used for Plaster of Paris, this gypsum is very soft and crushes easily. With regards to the softness - I wrapped the last piece I had into a cloth and crushed it using the back of a tablespoon.
There is only one gypsum mineral, and it is scientifically known as gypsum, which is a hydrous calcium sulfate. There are minerals similar to gypsum such as anhydrite and talc, but there is only one gypsum mineral.