Abalone Brooch and Have No Idea on the Other!

Another unknown to me. These two pieces were also in the bottom of the box bought at auction over 30 years ago, along with the (what I found out,) yesterday posting here was a Dragon's Breath Opal necklace. I think the brooch is a Abalone Mother of Pearl. It is marked Sterling on the back with a pin clasp. C, maybe, or a barrel. Looks like her neck might have been cracked too? The other piece, I have no clue. It's about the size of a dime. And, it's sitting sideways here! The middle stone is on a little tiny cut butterfly. Surrounded by other stones, which one is missing. It's a pin with one of those push type fasteners. Maybe a lapel pin or a tie pin? Only markings on it that I can see and can't is some Pat. mark with numbers on the fastener. And, I have no idea what it is made of. Looks like diamonds, but I wouldn't hold my breath! ;-) Any ideas? All welcomed. :-)