Know the Difference

Lab-Grown vs Natural Diamonds

Lab-grown and Natural diamonds are both real diamonds: pure carbon in the same cubic crystal structure. They share the same brilliance, fire and hardness. The differences are how they form and what's inside the stone at a microscopic level.

Lab-grown Natural
Composition Pure carbon (C) Pure carbon (C)
Crystal structure Cubic Cubic
Brilliance (refractive index) 2.42 2.42
Fire (dispersion) 0.044 0.044
Luster (reflectivity) 17.2% 17.2%
Hardness 10 Mohs 10 Mohs
Origin Grown in a lab (CVD or HPHT) Mined from the earth
Time to form 2–4 weeks 1–3.5 billion years
Diamond type Mostly Type IIa (nitrogen-free) About 98% Type Ia (nitrogen present)
Typical inclusions Metallic flux or graphite specks Feathers, mineral crystals, clouds
Certification IGI, GIA (report says lab-grown) GIA, IGI