What's the difference between diamond, moisssanite, and white sapphire?
Each of these gemstones is an entirely different mineral, with its own chemical makeup and inherent properties. All are clear stones, and the attributes of each can be very similar in some cases, or pretty darn different in others. It can be easy to see a clear gem, and assume it'll have the same properties as diamond (the stone you're likely most familiar with), but it's nice to know some key differences before deciding which stone is right for you. This post will have some facts, some photos, and some personal opinions -- because, what's the fun if I can't infuse a little personal opinion?
Diamonds are the hardest mineral on earth, ranking at a 10 on the Moh's Scale of Hardness. (If you're not familiar with the scale, take a peek at my post on the Moh's and stone durability.) Hardness is an important feature for an everyday ring meant to be worn for years. Diamonds also have wonderful fire and brilliance, producing that sparkle we all know and love from diamonds. Because of their amazing ability to reflect light back up to our eyes, it means they'll sparkle even when dirty. In a perfect world, your rings would be clean all the time and you'd remember to remove them every time you wash your hands. The reality, however, is that soap scum buildup, water residue, lotions, etc. will cause gunk buildup behind your stone. Even with that gunk, diamonds are so good at creating sparkle, they don't need a clean background. A clean stone will be even more blinding, but a dirty diamond will still sparkle. As I like to say, a diamond can even sparkle in a dark room.
Diamonds come in a range of qualities, which means there are a range of clarity and color grades. For my clear/white diamonds, I typically stay in the VS - SI clarity range, and E - H color range. That translates into high-end clarity, nearly colorless diamonds. For those who want a very white stone, diamonds are a fantastic choice. The downside? -- the high quality diamonds I use are pricey. They're also mined from the earth, which some clients may prefer to avoid. Though we've made great strides toward ethical diamond mining, the industry is still fraught with many issues.
I use Forever Brilliant™, Forever One™, and Supernova™ moissanites, so I'll be using them for my comparison. (If you're unsure of what moissanite is, take a peek at their website first.) These moissanites grade at colorless (Forever One and Supernova) and near-colorless (Forever Brilliant), with eye clean clarity, so they're very similar in clarity and color when compared to the high quality diamonds I use. Some fancy shapes of Forever Brilliants are a bit warmer than others, so that can be a consideration if you're looking for a colorless stone. Moissanites' sparkle is as great as diamond, even in a dark room or when your ring is freshly cleaned. A major bonus is their durability, which ranks second only to diamond, and is one of the hardest materials on earth (even harder than sapphire or ruby).
Because it's a created gem, it's free of environmental and social issues, making it the most ethical choice. It's crafted right here in the US and is certified as USA made. This can be a downside for clients who will only consider a gemstone mined/originated from the earth. Of all the white gemstone alternatives, moissanite looks and behaves the most like diamond. When viewed side by side, diamond and moissanite are typically indistinguishable. (Case and point, take a peek at my Instagram video.)
White sapphires rank at a 9 on the Moh's Scale, giving it a top 3 spot for hardness. Sapphire isn't as durable as diamond or moissanite, but it's still one of the hardest gemstones. It's a great option for someone looking for a stone from the earth (rather than a cultured or lab-grown stone). White sapphire is also a very affordable price point.
The major downside to white sapphire is it requires frequent cleaning. Sapphires inherently don't have the same ocular properties as diamond or moissanite. They have a lower refractive index and lesser fire (less sparkle). That means that as the stone gets dirty (soap scum buildup beneath it, lotions, even simple water spots), its facets won't continue to reflect as successfully as a dirty diamond or moissanite. The better sparkle of a diamond or moissanite means that even when there's dirt beneath it or water spots, it's able to reflect light back up to the eye. Sapphire, however, appears more transparent and looks best with a clean background. In order to keep your white sapphire looking the way it did when you received it, you'll have to clean it frequently. Cleaning can be done using an at home method, or just pop into a local jewelry store and have them use the ultrasonic cleaner.
Although sapphire is a very hard mineral, it can show signs of wear after years of wearing it regularly. It depends on how hard you are on your hands, or if you take care to remove your ring when doing activities. Sapphires can get a sort of "frosted" appearance after many years as the tiny edges of their facets wear. (Think the frostiness of sea glass, but just at the edges where the facets meet.)
There are several other clear/white minerals, which are often seen as engagement ring alternatives. White zircon, white topaz, and cubic zirconia (CZ) are sometimes confused for diamond/moissanite/white sapphire. They're really affordable, so why not use them? The main reason I'd advise against topaz, zircon, or CZ goes back to durability. CZ ranks at 8-8.5, topaz ranks at an 8, and zircon is just a 6-7.5 on the Moh's Scale. All will show signs of wear very quickly: scuffing (gives sort of a frosty/milky appearance to the stone), or even worse -- chipping, breaking, or cracking open entirely.
I'm sometimes asked by clients if I can set a topaz or CZ in a setting for now, and then they'd save up and replace it sometime with a more durable stone. I completely understand the need to stay within your budget, and I never try to talk a customer into spending more than they feel comfortable with. But some options just don't make economical sense, and I think it's my responsibility to be up front about future costs. For example, to purchase one of my mountings with a CZ might save you $100 when compared to the same ring set with white sapphire. To then purchase a loose sapphire later on and swap it for the CZ will cost you a few hundred bucks. (This is also assuming the setting doesn't require building up or re-tipping prior to resetting, or sometimes even a complete remaking of the mounting.) In the end, you're spending much more money. And for an everyday ring, it's pretty much guaranteed that you would need to replace your CZ/topaz/zircon at some point.
That, my friends, is up to you. Hopefully I was able to provide some helpful info and opinions about each one. Now it's up to you to decide which gem will fit your lifestyle, budget, and philosophy best. If you have a specific question, say about a certain size or cut of gemstone, please don't hesitate to email me directly. I have thoughts on that as well ;)