A synthetic moissanite has more fire, and slightly less brilliance, than a diamond. This balance between fire and brilliance gives a moissanite its attractive appearance.
Also, a moissanite is doubly refractive while a diamond is singly refractive, adding fire to the appearance of a moissanite. The fire is the rainbow colours you see when you move the gem.
A synthetic moissanite is a diamond simulant; a material that imitates a diamond's appearance and is used in its place. This means that moissanites can be manufactured in quantity, making them readily available and less expensive than diamonds.
Although some of the light that strikes the pavilion of the synthetic moissanite leaks out more light than a diamond, the moissanite is very effective as a diamond simulant when it's set in custom-made jewellery. It is also a hard and lasting gem – its hardness is similar to that of a sapphire or ruby.
With the newest available synthetic moissanites, like those offered by Charles and Colvard and NEO, the colour is whiter and the appearance seems brighter. Moissanites have a slightly greenish or yellowish tint to them. With the Forever One or NEO The One created moissanites, the slight colour is minimized. NEO moissanites have an excellent cut.