What would you do?

So a bit of a moral dilemma has arisen. Well, I know what to do but I am tempted to do something evil.
For money.
:-)
I brought my mother to the grocery store this morning. When I got out of my car, what to my wondrous eyes did appear in the parking lot but a diamond ring in a 14K gold setting. A tiny, heart-shaped diamond that looks like a pre-engagement ring.

I took it home with me. It's on my pinky. I'm going to put it in my jewelry cleaner solution and bring it back. To the customer service desk. Really. Then if the young girl who lost it comes in looking for it, it will be there for her.
I'm nice, I know.

UPDATE: I just cleaned the ring. It's sparkly.