A 4 carat lab diamond is a large diamond created by scientists in a lab. It's just like a mined diamond in every way. Even though it's big, it's usually cheaper than a mined diamond of the same size.
These diamonds can be made to be clear with few internal marks, and in various colors, from colorless to yellow, brown, and even blue or pink. They're cut just like mined diamonds to make them sparkle.
Lab-grown diamonds are more eco-friendly because they don't need to be mined. When you buy one, you can get a report about its quality, just like with a natural diamond.