An Explainer on coin sizes and masses:

Right now, stealing dollar coins is far more efficient on a pound-by-pound basis than stealing any other American coin in circulation.

This reminds me of a toll-booth heist in NH back in the 70s or 80s. The crooks ended up in the woods near the house I grew up in (before we lived there). We found a pile of coins out in the woods where one of the bags, we guessed, split open. The store clerks sure looked at us kids funny when we used dirt covered change to buy our candy bars...