Dean Davidson's best-selling earrings, worn by Meghan Markle. The Signature Midi Knockout Studs feature multi-faceted, brilliant-cut gemstones that make an impact for both day and night. Gemstone: Iridescent Sky Blue (man-made). This soft blue synthetic gemstone is handcrafted as a doublet, a technique that lends it extra iridescence through a mother-of-pearl backing. Metal: DD Signature Brushed Gold Plated Over High-Quality Brass. Gemstone Diameter: 7mm