From the 1930s, this is a 5 inch piece that has 4 sections of Mother of Pearl. A slit on each end piece with wear you would sew fabric for a belt.
This piece does not open in any way, so this would go on the front of a belt, and then the belt would either hook or tie in the back.
Silvertone metal connect the shell pieces.
Metal is lightly tarnished/dull, otherwise excellent condition.