Is a fluoride-arsenate of calcium that is at least partially isomorphous with apatite,hedyphane and mimetite. The formula is Ca5(AsO4)3F and hardness 4-5.
It has a good reaction of orange red under the short wave. It comes from a remote area:
Tjaktjajaure Lake, Tjamotis, Jokkmokk, Lappland / Northern Sweden. Uncommon.