[bonesmccoy]

If it is a powder composed of spores, it would not be possible to do gram stain to ID the spore. Only if you plate the organism can you positively ID via microscopy.

I have to think the US military has labs stationed in forward positions.

If not, I volunteer!

[RANGERAIRBORNE]

OK, my days of college microbiology are long behind me- but it still seems to me that this "powder" could be Gram's-stained and at least identified as being consistent with Bacillus anthracis spores or just lactose or talcum powder.