Lux 14kt Gold Fill and black Cubic Zirconia studs. The studs measure approximately 4mm and the ball backs approximately 12mm.  Why use GoldFill? Goldfill is such a wonderful material. It gives the look of 14kt Gold at a fraction of the price. Also known as "rolled Gold" it is a layer of precious gold metal pressure bonded to another metal usually another yellow metal like brass. Not to be confused with its cheaper cousin gold plating, GoldFill contains far more of the precious metal, is tarnish resistant and EU regulated. It is currently more valuable than Sterling Silver and even Vermeil (sterling silver with Gold plating). It is a wonderful material, try it, we think you'll be impressed! Matching Items available.