If you've ever shopped for a ring and felt confused by the terms "carat" and "karat," you're not alone. They sound identical, but they mean completely different things. Understanding the difference will make you a smarter jewelry buyer — and help you get the most value for your money.
What is a Carat? (ct)
A carat is a unit of weight used to measure gemstones. One carat equals 0.20 grams. The higher the carat weight, the larger (and typically more expensive) the stone.
A few important things to know about carats:
- Carat ≠ size — carat measures weight, not physical dimensions. A 1ct moissanite and a 1ct diamond may look slightly different in size because they have different densities.
- Price jumps at milestones — a 1ct stone costs significantly more than a 0.9ct stone, even though they look nearly identical to the naked eye.
- Moissanite runs larger — because moissanite is less dense than diamond, a 1ct moissanite is actually slightly larger in diameter than a 1ct diamond. More sparkle, more presence, for less.
What is a Karat? (k or kt)
A karat is a measure of gold purity. Pure gold is 24 karats (24k). The lower the karat number, the more the gold is mixed with other metals:
- 24k — 100% pure gold (too soft for everyday jewelry)
- 18k — 75% gold (premium, used in fine jewelry)
- 14k — 58.3% gold (most common in the US)
- 10k — 41.7% gold (most affordable, most durable)
What About Sterling Silver 925?
At Sterling Hearts, our rings are crafted in sterling silver 925 — which means 92.5% pure silver alloyed with 7.5% other metals (typically copper) for strength and durability. The "925" is the purity stamp you'll find on authentic sterling silver pieces.
Sterling silver 925 is:
- ✅ Hypoallergenic and safe for sensitive skin
- ✅ Tarnish-resistant with proper care
- ✅ Strong enough for everyday wear
- ✅ The ideal setting for moissanite, opal, and cubic zirconia
Why Moissanite is the Smart Choice
When it comes to center stones, moissanite offers exceptional value. A 2ct moissanite heart ring delivers the same visual impact as a 2ct diamond — with more fire and brilliance — at a fraction of the price. That means you can go bigger, bolder, and more beautiful without compromise.
Our moissanite is D color grade, VVS1 clarity, and GRA certified — the highest quality available.
Quick Reference: Carat vs Karat
| Term | Measures | Used For |
|---|---|---|
| Carat (ct) | Weight | Gemstones (diamonds, moissanite, opal, CZ) |
| Karat (k/kt) | Purity | Gold jewelry |
| 925 | Purity | Sterling silver jewelry |
Shop Sterling Hearts
Now that you know your carats from your karats, explore our collection of premium moissanite, opal, and cubic zirconia heart rings — all set in sterling silver 925 and backed by our lifetime quality guarantee.