Trash it. Use it as fertilizer or burn it in small piles no more than 1" deep and 5-6" around.
I'm not sure how much you like your body parts, but if you like them and do not wish to be hurt, dispose of the stuff and buy new powder. There is no, I repeat
NO way to identify powder positively by the layman. The only true way to identify and unknown powder is to pressure bomb it and compare the results to known lots. Ask any powder company and they will tell you the same. Unless you have access to a proper lab (I think there are only 4 here in the USA) then you are out of luck.
I hear all the time that you can put powders side by side, measure a given volume and then compare weights to know and vice versa, small amounts in a large case and compare to know loads, yada-yada. All of them are BS, complete and total. If you don't believe it, I can pull a fast one on you and show you a rifle powder intended for the .338 Lapua that will mimic one of the SR pistol powders. Volume to volume, weight to weight, and they look identical. Sure would be a good way to make a fine gun into a grenade. Look at the dot powders, there is a huge difference between red and blue but they look a lot alike, huh! wonder why they use those little pieces of colored paper in them? Please just trash the damn stuff.
Okay, Rant over.