Best Diamond Alternatives: Moissanite, Lab Grown, White Sapphire and More
If a mined diamond is not right for your budget or your values, you have more choice than ever. But the alternatives are not equal. Some are real diamonds, some are tough gems with a very different look, and some will show wear within a few years. This guide compares the five you will see most often.
At a Glance
| Stone | What it is | Hardness (Mohs) | Look | Everyday durability |
|---|---|---|---|---|
| Lab grown diamond | Real diamond | 10 | Classic diamond sparkle | Excellent |
| Moissanite | Silicon carbide | 9.25 | Very bright, strong rainbow fire | Excellent |
| White sapphire | Colorless corundum | 9 | Soft, glassy shine, little fire | Very good |
| Cubic zirconia | Synthetic zirconium oxide | 8 to 8.5 | Bright and colorful when new | Fair; scratches and dulls over time |
| White topaz | Colorless topaz | 8 | Glassy, low sparkle | Fair; can chip and scratch |
Lab Grown Diamond
Strictly speaking, a lab grown diamond is not an alternative to diamond. It is a diamond, with the same properties as a mined one, grown in a lab instead of underground. It gives you the true diamond look and hardness for far less than a mined stone. The trade-off is low resale value. Read more in are lab grown diamonds worth it?
Moissanite
Moissanite is the closest look-alike among durable gems, and the most affordable of the top two. Its refractive index of about 2.65 is higher than diamond's 2.42, and it has more than twice diamond's dispersion, so it looks extremely bright with strong rainbow fire. At 9.25 on the Mohs scale it handles daily wear easily. It is not a diamond and should always be sold as moissanite. See is moissanite worth it?
White Sapphire
White sapphire is hard and durable, which is why it is sometimes suggested as a diamond alternative. Its refractive index is much lower, though, around 1.76, so it returns less light and shows very little fire. It tends to look glassy rather than sparkly, and it can look dull quickly when a film of oil builds up. It suits someone who wants a soft, understated shine.
Cubic Zirconia
Cubic zirconia is the least expensive option and looks bright and colorful when new. At 8 to 8.5 on the Mohs scale, it is noticeably softer than the stones above, so over years of daily wear its facet edges get scratched and worn and it can look milky. It is a good choice for costume jewelry or a temporary ring, less so for a ring you plan to wear for life.
White Topaz
White topaz is affordable, but it has low sparkle, and at 8 on the Mohs scale with a tendency to cleave it can chip or scratch. It is better suited to occasional-wear pieces than an engagement ring.
Which Should You Choose?
- You want a real diamond: lab grown diamond.
- You want the most size and sparkle for your budget, built to last: moissanite.
- You want a soft, understated shine: white sapphire.
- You need something temporary or very low cost: cubic zirconia.
For most engagement rings meant to be worn every day for decades, the two strongest choices are lab grown diamond and moissanite. Compare them side by side in Moissanite vs Lab Grown Diamonds, or read about moissanite vs cubic zirconia.
Quick Answers
What is the closest thing to a diamond?
A lab grown diamond, because it is a diamond. Among non-diamond gems, moissanite is the closest in look and durability.
Is moissanite better than white sapphire?
For sparkle, yes: moissanite is much brighter and has far more fire. Both are hard enough for daily wear.
Which diamond alternative lasts the longest?
Lab grown diamond and moissanite, the two hardest. Cubic zirconia and white topaz show wear much sooner.
Browse our moissanite engagement rings and lab grown diamond engagement rings.