For one money is this lot of eight plus one black glass coat or sweater buttons. They are just over one inch in diameter (1 1/16), and their back edges were hand ground. Although they are made of jet black glass, the front engraved design consists of very fine engraved pattern that reflect light. Eight of them must have been silvered in some way, because they have an attractive silvery gray look. One was not silvered, and that is why this lot is listed as "8+1" buttons, because eight are perfectly identical, and one has an identical pattern, but was not silvered and has a different tone (see picture of the two buttons with penny above). Two of the silvery black buttons have tiny nicks on the edge which you can see in one of the pictures.
They probably date before 1940, but could be a lot older. They were all strung together on a string, and I don't think they were ever used. They will be carefully individually wrapped. Never place garments with glass buttons into a clothes dryer.