These vintage Czech buttons are black glass with a molded dotted swirling pattern that is enhanced with gold. These buttons have glass shanks and measure 18mm or just under 3/4 inch in diameter. They have a small indentation in the middle in which I think you could set a tiny flat back rhinestone, although the buttons are lovely just as they are. These buttons are coming directly out of the original wraps to you. You will receive 4 of these beautiful vintage glass buttons.