36 vintage black glass buttons on their original display card - cut to catch the light .... Glorious..
You can see from the photos that they are faceted and they glint seductively when they catch the light
They are 9mm in diameter and have a shank moulded from the same piece of glass as the button.
I found these in boxes with French labels on, right at the very back of a big old dusty warehouse full of vintage buttons.