What’s the difference between a diamond and a moissanite? The Brilliance in a Moissanite is a 2.691 while a Diamond is only a 2.417. The Durability / Scratch Resistance on a Moissanite is a 10.00 while a Diamond is a 9.25. And the cost difference a Moissanite is about $400 per carat while I diamond is about $4000 per carat. However a moissanite is grown in a lab while diamonds are naturally grown. It was first discovered by Henri Moissan in 1893 while excavating a crater and