Synthetic Diamonds
Synthetic diamonds have carved a niche in the market, especially in recent years. Cubic zirconias were able to fool people for some time, but they can't compare to the beauty of a real diamond. CZs are cheap imitations of the real thing; they're heavier than diamonds (approximately two times as much), they only score an 8.5 on Mohs scale of hardness, they have a lower index of refraction, its excessive dispersion of light makes it look fake, its D-color perfection is too good to be true, and is a thermal insulator while diamonds act as thermal conductors. Recently, another stimulant has taken a share of the market: moissanite. Moissanite (silicon carbide) is not commonly found within the Earth, so what is being touted as an alternative to diamonds is synthetic. Moissanites, though seemingly closer to diamonds than CZs, are still flawed in comparison to the real thing. Though scoring a 9.5 on the Mohs scale, moissanites are lighter than diamonds and usually suffer from some kind of discoloration. Furthermore, due to the pricey manufacturing process of moissanites, it is not the most cost effective alternative to diamonds.