Moissanite vs Lab Grown Diamond: Which Should You Buy?
If you are shopping for an engagement ring in the Philippines, you have probably seen both moissanite and lab-grown diamond rings, often at very different prices. They can look similar in photos, but they are different stones. Here is an honest comparison to help you decide.
What is moissanite?
Moissanite is silicon carbide. It was first found in tiny amounts in a meteor crater, but natural moissanite is extremely rare, so all moissanite sold in jewelry is lab-created. It is hard, brilliant and durable, which makes it a popular diamond alternative.
What is a lab-grown diamond?
A lab-grown diamond is pure carbon, with the same crystal structure, hardness and optical properties as a diamond mined from the earth. It is graded with the same 4Cs and certified by labs such as IGI and GIA. Learn more in our diamond guide.
Side-by-side comparison
| Lab-grown diamond | Moissanite | |
|---|---|---|
| Material | Carbon (diamond) | Silicon carbide |
| Hardness (Mohs) | 10, the hardest mineral | About 9.25, still very hard |
| Refractive index | About 2.42 | About 2.65 |
| Fire (dispersion) | About 0.044, balanced white and colored sparkle | About 0.104, strong rainbow flashes |
| Grading | 4Cs, IGI or GIA reports | Not graded on the diamond scale |
| Price | Higher | Lower |
| Is it a diamond? | Yes | No |
Sparkle: how do they look different?
Moissanite has more than twice the dispersion of a diamond, so it throws bold rainbow-colored flashes, especially in direct sunlight. Some people love this. Others find it looks less like a diamond, particularly in larger stones. A well-cut diamond shows a balance of bright white light (brilliance) and colored fire, the classic "diamond look".
Durability for everyday wear
Both are excellent for an engagement ring you wear every day. A diamond is the hardest mineral and resists scratches best. Moissanite, at about 9.25 on the Mohs scale, is harder than sapphire and ruby and will also hold up well for a lifetime with normal care.
Price
Moissanite generally costs less than a lab-grown diamond of the same size. That said, lab-grown diamond prices have dropped a lot, so the gap is smaller than it used to be. For current peso prices, see our lab-grown diamond price guide. At Northcut, a 1.00ct lab-grown diamond solitaire in 14K gold is ₱40,900.
How do they test?
Many basic handheld "diamond testers" measure heat conductivity, and moissanite conducts heat much like a diamond, so it can pass as diamond on those testers. Jewelers use a dedicated moissanite tester (electrical conductivity) to tell them apart. A lab-grown diamond tests as diamond on both, and advanced lab equipment is needed to tell lab-grown from mined.
Which should you choose?
Choose a lab-grown diamond if…
- You want a real diamond, with the classic diamond look.
- You want a certified grade (IGI or GIA) you can verify.
- You want the hardest, most scratch-resistant stone.
Choose moissanite if…
- Your top priority is the lowest price for a large stone.
- You love strong, rainbow-colored sparkle.
- It does not matter to you whether the stone is a diamond.
Frequently asked questions
Is moissanite a lab grown diamond?
No. Moissanite is silicon carbide, a completely different mineral. A lab-grown diamond is pure carbon, the same as a mined diamond.
Can you tell moissanite from a diamond?
Often yes, in person, because of moissanite's rainbow sparkle. A jeweler can confirm it with a moissanite tester.
Will a lab-grown diamond pass a diamond tester?
Yes. It is a diamond, so it tests as one.