Hardness refers to a gemstone's resistance to being scratched or abraded and is commonly expressed as a number ranking (1 being the softest and 10 being the hardest) on Mohs relative hardness scale.
Moissanite ranks 9.25 on the Mohs scale making Moissanite one of the hardest gemstones on earth. It's unusually high hardness makes scratching and abrasions very rare, even after many years of daily wear and tear.
Moissanite's ability to resist abrasion and scratching easily outranks and is more than double (120%) the hardness of any popular diamond simulants such as Diamond Nexus (CZ), Russian Brilliants (CZ), or Sona Diamond (CZ).