Montana blue Czech Glass Cathedra with Copper sprinkles create these beautiful earrings! Antiqued copper flowers and ear wires complete the look! Copper Ear Wires. The art of glassmaking dates back to Roman times. From the earliest days, Czech glassmaking set the standard for Europe and the world. There are four main colour groups, Red, Blue, Green and Brown. Blue and Green Czech glass are the famous products of the former Czechoslovakia renowned worldwide over the last two centuries.Czech glass beads are known for their sparkling cuts and vibrant colors.