Genuine 5mm amethyst gemstones sit inside these 9ct yellow gold square-shaped stud earrings. Amethyst is the February birthstone, which makes this pair of earrings a perfect match for anyone with a February birthday. Stamped with a 375 metal mark, these studs have an 8mm face size, 11m distance from front to back and a 0.65mm pin width. Held in place by butterfly backs, they weigh just less than half a gram.