18ct white gold 0.75ct lab grown round brilliant cut diamond four claw set stud earrings (image not to scale) 0.75ct total lab grown diamond weight. G colour, Si2 clarity certificated. A lab grown diamond is a real diamond that is grown in a laboratory rather than naturally within the Earth's core, it has the same chemical and physical structure as a natural diamond. The main difference between lab grown and natural diamonds is the origin and rarity. To find out more information about lab grown diamonds please read our blog.