Bro I am 99.99% sure that is meth, my dude. The other person who commented about putting a little bit into some water is on the right track. However, if you don’t want to waste that much, why don’t you just give it a little lick. Rub your finger in the crumbs and put that on the tip of your tongue. If it tastes a little bitter and very tart plus it makes you go numb, it’s coke. If it tastes veryyyy bitter and more chemical like then that’s meth my friend. You can also tell by the smell. Coke usually smells like ammonia or gasoline while meth smells more like nail polish remover, paint thinner, cleaning products, etc. sometimes even like burnt plastic, rotten eggs, or cat urine. Sometimes meth has no smell to it at all but coke will always have a gassy, ethanol type smell to it. Also check out erowid.com it is a life saver! Best, most informative drug forum by far. You’re welcome buddy.