Durability is a big factor when considering the right gemstone for your engagement ring. It is a piece of jewelry that should last a lifetime after all.
Fortunately, Moissanite is the second hardest gemstone on Earth (after Diamond) and is more durable and scratch resistant than other popular gemstones like Sapphires, Rubies, or Emeralds. While all gemstones can become scratched (including Diamonds), Moissanite ranks as one of the top options of gemstones to be able to withstand daily wear. When gemstones do become scratched, it can easily be polished to look like new again.
Moissanite’s chemical formula is Silicon Carbide, which is the same formula used in many bulletproof vests and metal cutting saws. Just like Diamond saws, Moissanite saws are commonly used to cut and slice other materials. This means Moissanite is extremely durable and can withstand the occasional blunt force or hand smashing experienced in daily wear.
While many gemstones don't do well with heat, Moissanite has an incredibly high melting point of 2730 °C, which will withstand a jeweler’s torch during resizing or repairs to the ring setting. Moissanite's heat tolerance should even withstand house fires that typically burn at 1,100 °F. The color of the Moissanite does change color temporarily while its under heat or a jeweler's torch but will revert back to its original color once it cools down.
While Moissanite and Diamond are two of the hardest and most durable gemstones, it is worth noting that no gemstone is indestructible. All gemstones are susceptible to chips and cracks if it encounters enough acute force. Inclusions in the gemstone is to blame for majority of chips and cracks. The more inclusions a gemstone has, more more likely of the chance of fracture or breakage. Moissanite has been lab designed to have little to no inclusions so the possibility for chips and cracks are much lower.
During the ring setting process, a lot of pressure is being applied to a gemstone. Once in a while, stones (including Diamond) does get chipped. This is why jewelers have to purchase insurance on their end to cover these occasional incidents. When chips happen, usually the jeweler will set the stone in a way to have one of the prongs cover the chipped areas. When the stone completely shatters (which also happens), the jeweler's insurance will help replace a new stone in equivalent value/quality for you.
Moissanite is an incredibly durable gemstone and there shouldn't be a need to replace it at any point in one's life unless the jeweler didn't set the stones in properly and they fall out.