Why Moissanite?

The Aumire Journal · Education | 9 min read

Quick Answer: Moissanite is not a diamond — it is silicon carbide, a distinct gemstone with its own optical personality. It ranks 9.25 on the Mohs scale (diamond is 10), throws noticeably more rainbow fire, and costs roughly 5–10% of a natural diamond and 60–90% less than a lab-grown diamond of the same size. Choose moissanite if you want the largest, brightest stone for your budget; choose a diamond if certification, resale value, or the word "diamond" itself carries real weight for you.

The ground has shifted under this question. According to The Knot's 2026 Real Weddings Study, lab-grown diamonds now account for 61% of engagement ring center stones in the US — while the average amount spent on an engagement ring fell to about $4,600, even as the average center stone grew to 1.9 carats. Couples are not spending less because they want less presence. They are buying smarter, and increasingly the smartest buy of all is not a diamond at every price.

First: What Each Stone Actually Is

Diamond is pure carbon, crystallised over billions of years, or (in the lab-grown case) over a few weeks in a reactor. Chemically and optically, a lab-grown diamond is a diamond — the same material, the same 10 on the Mohs scale, graded on the same 4Cs.

Moissanite is silicon carbide (SiC). It was first identified in 1893 by French chemist Henri Moissan inside a meteorite crater in Arizona; naturally occurring moissanite is so rare that essentially every stone sold today is created in a laboratory. That origin makes it no less real a gemstone — it simply means it is a different mineral, not a copy of another one.

This distinction matters, because it settles the most common question we hear: moissanite is not a "fake diamond." Cubic zirconia is a diamond simulant — a soft, cloudy material that dulls within a year or two. Moissanite is a permanent gemstone that will outlast the person wearing it.

The Comparison, Point by Point

Factor	Moissanite	Diamond (natural / lab)
Composition	Silicon carbide (SiC)	Pure carbon
Mohs hardness	9.25	10 — hardest known natural material
Refractive index	2.65–2.69 (more brilliance)	2.42
Fire (dispersion)	0.104 — ~2.4× diamond	0.044
Light behaviour	Doubly refractive — rainbow flashes	Singly refractive — white sparkle
Specific gravity	3.21 — ~10% lighter, looks larger per carat	3.52
Toughness	No cleavage planes — very chip-resistant	Harder, but can chip along cleavage
Colour	Colourless DEF available; large stones may show faint tint	Graded D–Z; holds white consistently
Price, 1 carat	~$300–800	Lab ~800–2,000 · Natural ~4,000–8,000+
Certification	GRA (moissanite standard)	GIA / IGI (global standard)
Origin & ethics	Lab-created, mining-free	Lab: mining-free · Natural: mined
Resale value	Very limited secondary market	Natural retains ~30–50% of retail

The One Difference You Will Actually See: Sparkle

Every other spec is close. Sparkle is not. Moissanite's refractive index is higher than diamond's, and its dispersion — the splitting of white light into colour — is roughly two and a half times greater. In practice:

• In sunlight or under spotlights, moissanite throws vivid rainbow flashes. Enthusiasts call it fire; critics call it a disco ball. It is the single most noticeable tell.

• In normal indoor light, most people cannot distinguish the two at a glance — you would be looking at someone's hand, not a stone under a loupe.

• Double refraction: moissanite splits light into two rays, so facet edges can look very slightly softened or doubled under magnification. Diamond does not do this.

Our honest read: if you love colour and drama, moissanite's fire is a feature. If the classic white, restrained sparkle is the look you have pictured since you were sixteen, say so out loud — it is a legitimate reason to choose diamond.

Choose with your eyes, not with the price tag. Both stones last a lifetime; only one of them will make you look at your hand and smile.

The Price Math, Without Spin

Here is what your budget actually unlocks in 2026 retail terms (near-colourless stones, quality settings):

Budget	Moissanite	Lab-grown diamond	Natural diamond
$800	1.5–2 ct in solid gold	~0.3–0.4 ct	—
$1,500	2–3 ct, halo or pavé	~0.5–0.7 ct	—
$3,000	3 ct+ with a premium setting	~1–1.5 ct, IGI certified	—
$8,000	Anything in the catalogue	2 ct+, D–F	~1 ct, GIA G/VS1

Two things worth knowing. First, lab-grown diamond prices have fallen roughly 40–60% since 2020 as CVD production scaled — good news for buyers, bad news for anyone who bought in 2020 expecting resale value. Second, moissanite's advantage widens as size increases, because diamond pricing climbs exponentially with carat weight while moissanite's climbs far more gently. A 3-carat moissanite can cost one-fortieth of a comparable natural diamond.

Three Situations Where Diamond Really Is the Better Buy

We sell moissanite, and we will still tell you this:

• Resale or heirloom value matters to you. Natural diamonds retain roughly 30–50% of retail on the secondary market. Moissanite's resale market is thin. If you may upgrade, sell, or pass the ring on as a financial asset, buy a diamond.

• The word "diamond" carries emotional weight in your family or culture. That is not vanity — symbols have real value. Pretending otherwise helps no one.

• You want the quiet white sparkle. If the rainbow fire reads as "too much" to you, no amount of money saved will make you love the stone.

And Three Where Moissanite Clearly Wins

• Size is the priority. The same budget buys two to three times the visual presence.

• You want it mining-free and conflict-free, without the diamond price. Both lab diamond and moissanite avoid mining; only one of them costs a fraction of the price.

• You are hard on your jewellery. Moissanite has no cleavage planes, so it resists chipping on impact, and its 9.25 hardness means decades of daily wear with no loss of polish.

Will Anyone Be Able to Tell?

Probably not by looking — but be aware of two details. A standard thermal diamond tester will read moissanite as diamond, because silicon carbide conducts heat similarly to carbon. An electrical-conductivity tester will separate them. And in direct sun, a trained eye will see the fire. Most owners tell us the honest answer they give friends is simple: "It's moissanite — and yes, I chose it."

Caring for Either Stone

Both are cleaned the same way: warm water, a drop of mild dish soap, a soft toothbrush, a thorough rinse and a lint-free cloth. Diamond (natural and lab) tends to attract skin oils faster and dull between cleanings; moissanite stays clear longer but can develop a rainbow-tinged oil slick film — removable in minutes.

Frequently Asked Questions

Q: Is moissanite a fake diamond? No. It is a distinct gemstone — silicon carbide — with different chemistry and optics from diamond. A simulant (like cubic zirconia) imitates diamond's appearance and degrades; moissanite is a durable, permanent stone in its own right.

Q: Does moissanite pass a diamond tester? Yes, on a standard thermal tester — its heat conductivity is close to diamond's. Electrical-conductivity testers can distinguish the two. Either way, an honest seller will label the stone correctly on your receipt.

Q: Will moissanite go cloudy or yellow over time? No. The crystal does not change colour. Cloudiness is almost always a removable surface film of oils and soap — the "oil slick." The myth comes from older, lower-grade stones.

Q: How much cheaper is moissanite than a lab-grown diamond? Typically 60–90% less at retail. A 1-carat moissanite runs roughly $300–800 versus $800–2,000 for a comparable lab-grown diamond, and the gap widens above 2 carats.

Q: Can you wear moissanite every day? Yes. At 9.25 Mohs it resists scratching from virtually everything you meet in daily life, and it has no cleavage planes, so it is highly chip-resistant. An annual prong check is still wise for any ring.

Q: Does moissanite hold any resale value? Very little — the secondary market is limited. Natural diamonds retain around 30–50% of retail. Treat moissanite as a piece you buy to wear, not to sell.

---

Every Aumire stone is colourless DEF, VVS clarity, cut to maximize light — set in solid gold, priced without the diamond markup. Explore the Collection →