Moissanite is lighter than diamond, so carat weight doesn't directly correspond to visual size. Learn how to compare stones accurately.

Why Carat Weight Differs

Moissanite has a specific gravity of 3.22, while diamond is 3.52. This means a moissanite of the same diameter weighs approximately 10-15% less than a diamond. A 6.5mm moissanite weighs ~0.88ct but looks like a 1ct diamond.

Size Comparison Chart

TABLE:

Diameter (mm)Diamond EquivalentMoissanite Actual Weight
5.0mm0.5ct0.44ct
6.0mm0.8ct0.70ct
6.5mm1.0ct0.88ct
7.5mm1.5ct1.32ct
8.0mm2.0ct1.76ct

How Holycome Lists Stones

We list both diamond equivalent size (mm diameter) and actual moissanite carat weight to avoid confusion. This ensures customers know exactly what they're getting.

Pricing by Size vs Weight

Moissanite is typically priced by size (mm) rather than weight, since visual size is what matters for jewelry. This makes comparison shopping easier for customers.

Frequently Asked Questions

Why is moissanite lighter?

Silicon carbide (moissanite) has a lower density than pure carbon (diamond), so the same volume weighs less.

Should I buy by carat or mm?

For jewelry, buy by mm size — that's what you see. Carat weight is secondary for moissanite.

Conclusion

Understanding the size-weight relationship helps you and your customers make informed choices. Holycome provides both measurements for every stone. Contact service@holycome.com for our stone selection guide.