18ct white gold lab grown round brilliant cut diamond four claw set pendant on a white gold 18″ chain. (Image not to scale) 1ct lab grown diamond, certificated D colour, VS1 clarity. 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.