Synthetic Moissanite or Diamond. Which way to go? For colourless gems Diamonds are always going to be the first choice for hardness, toughness and durability. Synthetic Moissanite is often promoted as a great diamond alternative because its almost as hard as diamond right?. Almost as hard but not really anywhere near as hard as a diamond. Knoop hardness for synthetic moissanite 3000. Diamond 8000. 2.6 times harder! But as a diamond pretender I think the biggest let down of moissanite is the fact its easily separated visually from diamond by its double refractiveness and unique inclusion patterns that look nothing like a diamond. This double refractiveness gives it a fuzzy out of focus look as you turn the gem which you just don’t get with diamonds as they are singly refractive so light return in diamond is sharp and crisp. The main issue with moissanite is durability. Over the years I have had many come through the workshop with very large cookie cutter type chips out of them. Now diamonds can also chip but for the sheer number of diamonds in the market vs moissanite the number of damaged moissanite I see far out weight the number of damaged diamonds. Pretty much every moissanite that comes through our workshop has some sort of damage. Just as cubic zirconia, another diamond simulant will have. So Synthetic moissanite as a diamond alternative I say no but for one option…. Coloured synthetic moissanite you can get some amazing colours that make it a great dress ring option. Some amazing teal colours make it a more a great sapphire alternative. Just always remember its not as tough as you think so wear it with care! My advice if looking at reducing the cost of your diamond purchase go with Lab grown diamond over synthetic moissanite and other diamond simulants.
For the nitty gritty differences in diamonds vs Synthetic moissanite this is a great article from the GIA https://www.gia.edu/doc/Winter-1997-Gems-Gemology-Synthetic-Moissanite-Diamond-Substitute.pdf