Although labeled at the time Mangan-Apatite, this is scientifically/technically Apatite-(CaF) with small trace manganese present (there is a long article on this on MINDAT). Nevertheless, it is neat, blue, apatite as far as I am concerned as a collector. It is a really elegant miniature of this rare style, with muscovite. Ex. Ken Hollman Collection - and note the old label from Charlie Key in his early dealer days in the 1960s or early 1970s.