Moissanite Oval Engagement Rings: How They Compare to Diamond

Moissanite is a genuine gemstone, not a simulant like cubic zirconia — originally found in a meteor crater and now lab-created for jewellery use. On an oval cut, its differences from diamond are more visible than on a round, for reasons worth understanding before choosing between them.

The core difference: fire versus brilliance

Diamond and moissanite both sparkle, but differently. Diamond's refractive index produces predominantly white brilliance with flashes of colour (fire) at certain angles. Moissanite has a higher refractive index and disperses light into more colour more of the time — what jewellers call more "fire." Some people love this; it reads as extra sparkle. Others find it looks slightly less like a traditional diamond, particularly in direct sunlight, where moissanite can throw more visible rainbow flashes than a diamond of comparable size.

On an oval cut specifically, this difference is more noticeable than on a round brilliant, because the oval's larger visible table (the flat top facet) shows more of the stone's light behaviour at once. If matching a diamond's exact look is the priority, this is the detail to see in person before deciding, ideally in both indoor and outdoor light.

Hardness and durability

Moissanite rates 9.25 on the Mohs hardness scale, just below diamond's 10 — still hard enough for genuine daily-wear durability, and harder than most other gemstones used in jewellery. In practical terms, both moissanite and diamond will hold up to decades of daily wear without needing replacement, which isn't true of most colour gemstones.

Price

This is where moissanite's real advantage sits: a moissanite the visual size of a 1ct diamond typically costs a small fraction of even a lab grown diamond of that size, let alone a natural one. For an oval shape specifically — where visual size already reads larger than the carat number — a larger moissanite centre stone is achievable at a price point that would only buy a much smaller diamond.

Resale and perception

Moissanite doesn't carry the same resale value or cultural weight as diamond, and it can be identified as moissanite (rather than diamond) by a jeweller using standard testing equipment. For some buyers this is irrelevant; for others, the fact that it will eventually be recognisably "not diamond" if closely inspected matters. This is a personal decision, not a quality issue — moissanite isn't a lesser stone, it's a different one.

Common questions

Can you tell moissanite from diamond by eye?

Most people cannot in typical indoor lighting, but moissanite's extra fire (coloured flashes) is more visible in direct sunlight and to a trained eye, particularly on larger stones or elongated cuts like oval where more of the stone's surface is visible.

Is moissanite as durable as diamond for daily wear?

Yes, functionally — at 9.25 on the Mohs scale it's more than hard enough for an engagement ring worn every day, well above the hardness of gemstones like sapphire or emerald that are also used in fine jewellery.

Is moissanite cheaper than lab grown diamond?

Yes, significantly — moissanite typically costs a fraction of even lab grown diamond prices for a visually comparable size, making it the most budget-efficient way to a larger-looking oval centre stone.

See our oval diamond and lab grown ranges in Oval Engagement Rings.