SOLD AS A PAIR. Presenting the Gwen Lab-Grown White Sapphire Drop Earrings. Crafted with 6 carats of lab-grown white sapphires in sterling silver. The Fine Print: Metal: Sterling Silver Stone Type: Lab-grown white sapphire Stone Shape: Round cut Closure: Leverback Carat: 6.0 CTW DEW lab-grown white sapphires What is Lab-Grown?