Moissanite is the world's most brilliant gem. It is a naturally occurring stone that is optically indistinguishable from a diamond although it is chemically and compositionally different. To the naked eye, it is extremely hard to tell the difference between a diamond and a moissanite. Even jewelers may not be able to distinguish between moissanite and diamond without using a loupe (a special magnifying glass used by jewelers). The single greatest visual difference between a moissanite and a diamond is that a moissanite is actually more sparkly than a diamond.
What we think of as sparkliness is really refractiveness, or how well a gemstone can bend the light. Moissanites are more refractive than a diamond with a refractive index of 2.65 vs 2.42 for diamonds.
Moissanites are durable and strong like diamonds - they are ranked a 9.25 on the Mohs scale of hardness, second only to diamonds which are a 10, but significantly harder than an emerald (7.5) or a ruby (8) or even a sapphire (9). Your moissanite jewelry is designed for years of daily wear.