Moissanite vs White Sapphire: How They Compare

Moissanite and white sapphire are two of the most popular clear alternatives to diamond. Both are hard enough to wear every day and cost far less than a diamond of the same size. They look quite different, though: moissanite sparkles more than a diamond, while white sapphire has a softer, quieter shine. Here is how they compare on sparkle, durability and everyday wear.

What each one is

White sapphire is colorless corundum, an aluminum oxide and the same mineral as blue sapphire and ruby. Sapphire comes in every color except red, which is ruby, and the colorless kind is sold as white sapphire. It is mined, and it is also grown in labs: lab-grown sapphire is durable enough to be used for the windows of supermarket scanners.

Moissanite is silicon carbide. It was first found in 1893 in a meteorite crater, and the moissanite used in jewelry today is created in a lab.

Sparkle

Shown: Daisy Round Moissanite Halo Engagement Ring

This is where the two differ most. The refractive index measures how strongly a stone bends light, and a higher number means more light returned to the eye as brightness. Moissanite's is 2.65, above diamond's 2.42. White sapphire's is about 1.77, so it returns much less light and looks calmer and more glassy.

Dispersion measures how much a stone splits white light into rainbow colors, which jewelers call fire. Moissanite's dispersion of 0.104 is nearly six times that of white sapphire at 0.018, so moissanite flashes with color while white sapphire shows very little. If you want a ring that sparkles from across the room, moissanite is the clear choice. If you prefer a softer glow, white sapphire has its own appeal.

Durability

Both are among the hardest gemstones. Moissanite scores 9.25 on the Mohs scale and sapphire 9, behind only diamond at 10. Both resist scratching and keep their polish through daily wear, and both can still chip from a hard knock on an edge or a point. Take any ring off for sports and heavy work.

Size and weight

Sapphire is denser than moissanite, so a white sapphire weighs more than a moissanite of the same size: about a quarter more, judging by their specific gravities of 4.00 and 3.22. When you compare the two, compare millimeters, not carats.

Keeping the sparkle

Any clear stone looks duller with a film of lotion and skin oil on it. A quick soak in warm, soapy water and a soft brush every few weeks keeps either one bright. Our guide on how to clean a moissanite ring walks through it.

Which should you choose?

Shown: Petra Emerald Cut Moissanite Bezel Engagement Ring

• Choose moissanite if you want the look of a diamond or more: bright, fiery and lively in any light.
• Choose white sapphire if you want a mined gemstone, or prefer a soft, understated shine to sparkle.

Our moissanite engagement rings are set in 925 sterling silver with 18K gold plating and start at $88. For moissanite against the other popular stones, read Moissanite vs Diamond, Moissanite vs Lab-Grown Diamond and Moissanite vs Cubic Zirconia.

Common questions

Which sparkles more, moissanite or white sapphire?

Moissanite, by a wide margin. Its refractive index of 2.65 returns far more light than white sapphire's 1.77, and its dispersion of 0.104 gives nearly six times the rainbow fire.

Is white sapphire or moissanite more durable?

They are close. Moissanite scores 9.25 on the Mohs scale and sapphire 9, so both resist scratching and suit a ring worn every day.

Does white sapphire look like a diamond?

Less than moissanite does. White sapphire returns much less light than diamond and shows little fire, so it has a softer, glassier look. Moissanite bends light more strongly than diamond and shows more fire.

Is white sapphire a real sapphire?

Yes. It is colorless corundum, the same mineral as blue sapphire and ruby. Like blue sapphire, it can be mined or grown in a lab.

Browse our moissanite engagement rings.