Liz says: Moissanite Fine Jewelry what beautiful gems these are. This could be one of my most favorite collections. Free Shipping at Dressing To Impress. On the Mohs scale, Moissanite gemstones are a 9.25 on the Mohs Scale of Hardness, so they are suitable for daily wear. Diamonds are the hardest known mineral and receive a 10 on the Mohs Scale of Hardness. Because of this exceptional score, diamonds are very durable and ideal for daily wear.