A Deep Dive Into Moissanite’s Refractive Index and Fire
What gives Moissanite its legendary sparkle? The secret lies in its refractive index and dispersion — the way light travels through the stone and bursts into rainbow fire. In this post, we’ll explain the science behind the shimmer and how it compares to diamonds and other gems. Want the quick version? Read Why Moissanite Sparkles More Than Diamonds.
🔬 What Is Refractive Index?
The refractive index (RI) measures how much light bends when it enters a material. The higher the RI, the more light is slowed and bent — which means more sparkle. Moissanite has an RI of 2.65–2.69, compared to diamond’s 2.42.
That difference may seem small, but it’s visible. Moissanite bends and reflects more light, especially in low-light conditions like candlelight or dusk.
🌈 What Is Dispersion or “Fire”?
Dispersion refers to how a stone splits white light into rainbow flashes. Moissanite has a dispersion rating of 0.104 — almost double that of diamond (0.044). That’s why Moissanite often flashes colors while diamonds reflect more white light.
This phenomenon is what gives Moissanite its signature look: high brilliance, bold fire, and unmatched visual impact.
📸 How It Looks in Real Life
In bright daylight, Moissanite shines with intense white brilliance. Under warm light or indoors, it bursts into colorful sparkle. That’s why it photographs so well — and why it often looks “too sparkly” to those used to diamonds.
Still curious? See our Moissanite Carat Size Guide to visualize sparkle across sizes.
💎 Bottom Line
Moissanite’s optical performance is no accident — it’s rooted in physics. And at Jewel Eternal, we choose only D Color, VVS1 clarity stones cut for maximum brilliance. Learn more in Moissanite Certification.