7mm round white topaz natural gemstones in a rubover setting make for a seriously sparkly set of studs. As topaz is the November birthstone, these earrings make a stunning November birthday gift for a lady who enjoys wearing stud earrings. Made from sterling silver stamped with a 925 metal mark, they have a front to back distance of 1.5cm and weigh 1.4 grams as a pair. Butterfly backs easily secure them in place.