You definately want macro mode on. Even in macro mode my camera isnt good for small items close up but using a magnifying glass gets me to within a few inches.
You can also use a scanner, probably the best method for flat stuff like coins.
Not a button, but, what the heck, maybe someone might know what this guy is. He kinda looks like a leprechaun. Its metal (copper??) I found it digging several years ago, and I've never been able to find out what it is. The back is just the depression of the front.