I recently learned from a U.S. Fish & Wildlife inspector a trick for distinguishing bone from, for example, ivory or plastic. Under an ultra-violet light, bone will glow white, while plastic will not glow at all and just looks dark, and ivory will glow VERY bright white. It was a cool trick, and easier than the "burn and sniff test" or squinting at it through a magnifier to look for microstructure. The problem is getting a UV light.
