These stunning one of a kind earrings are Natural Australian Boulder Opals. They are set in a 22k gold bezels and a 14k gold underbezels and earring hardware. This style of hardware is sometimes referred to as "French backs" or "omegas" meaning that there is a post and a clip style paddle that flips up to keep them in the ears. There is no butterfly back because the earring back is all inclusive in the design. This also allows me to make these available to those of you who do not have pierced ears since I can easily remove the posts so that they are clips ready to ship to your door. They measure about 7/8" x 5/8".