Here is an example of a mourning pendant, and an excerpt from The Brat and the Brainiac II: Fear of Commitment, where I mention one of the characters' interest in and passion for mourning jewelry:
“Look what I found,” says Jason, handing me a pendant on a thin gold chain.
The finely painted miniature on the pendant was of a lady at a grave under a full moon. I know Miranda, with her interest in mourning jewelry, will love it and I congratulate him on his find.
“Yep,” I say, handing it back. “This is definitely one of them. You lucked out, man. They’re not that easy to find.”
“But why does she like something so morbid?”
“Because it’s not morbid to her. She thinks it’s sweet, that someone would wear a memento to their loved one.”
He thinks it over, and then he looks at me with a smile.
“I can see that.”