Moissanite and diamond are both excellent choices, but they serve different priorities.
Moissanite has higher refractive index (2.65 vs 2.42) and more fire than diamond. It sparkles more, especially in certain lighting.
Diamond scores 10 on Mohs scale, moissanite scores 9.25. Both are extremely durable for everyday wear.
A 1ct moissanite costs $300-$800, while a comparable 1ct natural diamond costs $4,000-$10,000+. Lab-grown diamonds fall in between at $1,000-$2,500 per carat.
Diamonds have some resale market, while moissanite has virtually none.
I went with moissanite and could not be happier. The sparkle is incredible. For the same budget I got a 2.5ct moissanite instead of a 1ct diamond. I have had mine for 3 years and it still looks brand new.
As a jeweler with 15 years experience, moissanite is a fantastic ethical and budget-friendly option. Serious diamond enthusiasts can sometimes tell the difference due to double refraction, but from normal viewing distance no one will know.