Was this "found" outdoors or was it "brought" outdoors?
EDIT: Ok, I got it now. It came from a barn. Get a disposable plastic cup and put some of the red powder in it. Add a little bit of water and watch what happens. If it seems like it's a dye for concrete, you should be able to tell fairly easy. Is possible it's simply powder for making red clay pottery. Did you notice any other pottery there? Any red concrete? Of course, it might have been left over from an in-house project, also.
Try to get a better pic of it.