Mother of Pearl buttons are that are vintage are from The 1800s 1900s . I have 4 cards 2 say mermaid pearls. Beautiful graphics on the card. These are in excellent shape. MOP are pretty translucent sheen of rainbow colors. Some have carvings on them they are more valuable to button collectors. They make beautiful jewelry. They symbolize royalty when they are shiny. Enjoy my etsy shop.