Key Takeaways. Moissanite offers a more affordable alternative to diamonds for engagement rings, with similar durability and greater brilliance and fire. While diamonds score a perfect 10 on the Mohs scale of hardness, moissanite is close behind with a score of 9.25, making both stones exceptionally durable.

The average size for the US couple is one carat, while most European couples stay around 0.5-0.6 carat. Those in the Mid-Atlantic region will spend nearly $2,000 more than couples in the Midwest. Younger couples tend to choose between one and two carat diamonds, while older couples seem to opt for the higher end.

0.3 ct is on the smaller side of engagement rings - meaning they can look beautifully dainty and subtle. It is widely considered that an engagement ring should have a diamond that is no smaller than 0.3 ct. Classic engagement ring designs require diamonds equal to or larger than 0.3 ct.