Carnival glass buttons from the Czech Republic. These are made by hand, one at a time, using hand-carved molds which are around 100 years old. The tiny buttons at the end of the cord are from 180 year-old molds. It's a family business, and they've just begun making them again.
They're very difficult to photograph, as they're so reflective, and so multicolored, although what shows against the fabric is pink or green, but mostly pink.