It was in with some of my flat buttons I was cleaning today.
It's a tad bid bigger than a dime and just about the same thickness .. I think it is brass with a bit of silver gild.
That is a good possibility..hadn't thought about that. I am not really sure what the image is, but the small roundish shape in the center may well be a small pineapple.
Here are some photos after a bit of cleaning. I think now that it probably depicts a lily or orchid, and is probably is from some sort of broach or other piece of jewelry.