Large and beautiful mother of pearl, abalone statement pendant; in sterling

This statement pendant is large: more than 2 inches wide at the widest point and about 3 inches long. It features a very white mother of pearl and a piece of abalone that looks exactly like the eye of a peacock feather. I'm not sure what the small rectangular gemstone is, but is has a blue and green cast to it and it shimmers The MOP has a small crack at the top near the bale, and the backing is flaking. Otherwise, it's in great condition. I bought it as a gift more than 20 years ago but never passed it along. It's never been worn. I think this is handmade.