Doug is the one who should be doing this but...
Your camera DOES shoot close ups

As soon as Vicky unloads her camera (she has the PowerShot A540) I'll show you some close up shots. It doesn't get as close to the object as my Lumix, but it really doesn't make a difference. I'll do my best to press her to unload the disk.

Then I'll give you some detail on how best to do it and give you some examples. For now, here's how it works with my Lumix (it'll be around the same for your camera).
At 6 mega pixels this next picture is really 39.111" by 29.333". I didn't even take this in "macro"; just in "program mode" with all the settings in auto except I shot it in the highest quality. I measured the distance between the coin and the lens and it was 4". I'm using a $3. adjustable aluminum fixture with a clamp on the end; one of those cheapo work fixtures. It's got a 60 watt equivalent fluorescent light-bulb with a full spectrum light. I covered the fixture with some of that "Press and Seal" stuff to diffuse the light a bit.. I use a tripod.
I don't know which software you use for photo editing, but you can't possibly view an entire pic that big on your monitor. Photoshop shows the pic at 33% it's original size. Here's what it looks like: (I use Photobucket)
Make sure you "click" on all the pics to enlarge them to their original size.
OK, now all I did was crop it a little to remove the surrounding area and see more coin:
What the heck, how about a little photoshop lighting affect?
To get even "closer", all I did was crop the same pic just a little more...
Now, that last shot isn't really that "clear" as there's some "halo" from the lens I guess... but shooting it in macro, it would be a bit clearer. I don't know, but I think the next to last shot is pretty good don't you? And that's WITHOUT using a macro feature. So, what I'm trying to say is, you don't necessarily have to be an inch from your coin or ring. Shoot in the highest quality and crop it.
I actually tried a macro shot after these and couldn't get the lighting right. The color of the coin above is much better. After doing this exercise, I probably won't shoot in macro anymore
Hope that helps....