These unique .925 Sterling Silver earrings feature high quality lab created blue opals and clear and purple Cubic Zirconia stones in a stylish design. There are 20 stones in all, 10 in each earring. ---Most Opals used in Jewelry are grown in a lab or, "Lab Created" like the Opals used in our Jewelry. Natural Opals are a soft stone and prone to cracking. Lab Created Opals are strong, more vibrant and have "Fire" and consistency to their coloration.