These brightly colored set of 6 triangle buttons are made using the millefiori technique, which is an adaptation of a glassworking technique.  Rods of clay in various shapes, colors and sizes are fused togther into a long "cane", from which thin slices are used to form surface designs.
The size is about 1" x 1".
These buttons are machine washable.  They can be line dried, but they can't withstand being drycleaned.