What’s the difference between simulated gemstones and genuine gemstones?

A genuine gemstone is one that is found in a natural source and has undergone treatment to help improve the cut or appearance.
Simulated stones (also called synthetic gemstones) are created in laboratories and emulate the characteristics and look of genuine gemstones. Simulated stones tend to be vivid in color as impurities are not present in a lab, and therefore do not modify the clarity or hue of the stone.
It is important to note that genuine gemstone is significantly more expensive than simulated gemstones.