They're minerals, Marie! Seriously, though, you just described my experience of the coin collecting community pretty well, too. You've got the people who have

They're minerals, Marie! Seriously, though, you just described my experience of the coin collecting community pretty well, too. You've got the people who have full collections of mint state Buffalo nickels, and you've got the people who collect coins with animals on them. A full boat of high grade Buffalo nickels can run you well over $50k, while you might not even have to put $50 into your animal collection to have a hundred nice pieces. About the only thing the coin community goes hard on generally speaking is cleaning or artificially toning coins (using chemicals to apply fake patinas or color). Those are no-nos, and you won't get any respect by doing them. The exception is ancient coins, which, since they're hundreds or thousands of years old, and frequently come out of the ground, usually need some cleaning to be presentable.