These tiny, delicate opal stud earrings are made of white opal and gold plated silver. They have an amazing glowing quality and when they catch the light, flecks of gold and turquoise light up from within. They are really beautiful and unusual. The stud or post earrings measure just 4mm (under quarter of an inch - very tiny!) across and are domed. The white opal is set into gold plated sterling silver. The butterfly backs are made from solid brass. These stud earrings come mounted on a linen presentation card. You also have the option of adding a well crafted glass presentation cloche. They transform the earrings into tiny historical specimens, and make a beautiful and engaging gift idea.