Iridescent Oyster Shell Buttons

Vintage iridescent gray smoky oyster shell sewing buttons. Mother of pearl MOP with simple minimalist design. From a button manufacturer that closed in the 1940s. After years of storage these had become extremely soiled but we've gently cleaned and polished them (no chemicals or oils).  Note: Because these are genuine shell, there may be slight variations in color or size and small natural imperfections- Buttons measure 9/16 inch (14mm), 2 hole sew through- Good condition as shown