In a SHTF scenario, you will want small denominations of precious metals. I've been doing it for 40 some years. A dollar bill is a piece of paper backed by nothing but confidence.
I read this all the time, but in a real SHTF scenario, I can't see gold, silver or diamonds being worth spit. I would think the real currency would be water, food, medicine, fuel, booze, tobacco, drugs and sex and not necessarily in that order.
