Moissanite vs Diamond: Hardness, Fire, Price and Resale

Moissanite and diamond look alike from a few feet away, but they are two different materials. Diamond is pure carbon. Moissanite is silicon carbide, a crystal that is almost never found in nature, so every moissanite in a jewelry store was made in a lab.

Pick diamond if you want the hardest stone there is, the classic white sparkle, and a piece that keeps some value. Pick moissanite if you want a big, bright stone for the lowest price and you are fine with more rainbow flashes and almost no resale. What you should never accept is a moissanite sold as diamond. Under the FTC Jewelry Guides, a seller has to disclose what a stone is, and calling a simulant a diamond is deceptive.

In our showroom collection, each diamond piece is listed as lab-grown or natural, like the Round Natural Diamond Ring 4.25 ct, 14K Yellow Gold at $6,000 or the Oval Lab Diamond Ring 2.47 ct, 14K White Gold at $3,600.

The physical numbers come from standard gem references (Mohs scale, refractive index and dispersion tables). They describe the material, not one brand, so they hold for any moissanite or diamond you see.

Hardness is resistance to scratching. Diamond sits at 10, and nothing in daily life scratches it except another diamond. Moissanite at 9.25 is still harder than sapphire and ruby (9) and far harder than glass (about 5.5) or quartz dust (7), the grit that slowly dulls softer stones. In practice moissanite holds a polish for decades of normal wear.

The gap shows at the edges. A diamond's facet junctions stay razor sharp. A moissanite worn every day for years can pick up tiny nicks on its sharpest edges, especially on a ring that hits door frames and gym bars. Hardness is not toughness, though: both can chip if struck hard on a point, which is why pear tips and marquise points need protective prongs whatever the stone.

Diamond is also denser. A 6.5 mm round diamond weighs about 1 carat; a 6.5 mm moissanite weighs noticeably less, which is why moissanite sellers quote millimeters or a "diamond equivalent weight" instead of true carats. When you compare listings, compare millimeters, not the carat number.

Two light effects make a stone sparkle. Brilliance is white light bouncing back to your eye. Fire is light split into rainbow colors. Moissanite has more of both on paper, and that is exactly what gives it away.

• In sunlight moissanite throws strong rainbow flashes, sometimes called a "disco ball" look. Some people love it. Others find it reads as not-quite-diamond.
• Indoors under soft light the two are very close. Most people at a dinner table could not tell.
• Under a loupe moissanite is doubly refractive. Look through the top at an angle and the back facet edges appear doubled. Diamond shows single, crisp lines.
• Body color older moissanite often showed a faint yellow or green tint. Newer colorless material is much whiter, but in big sizes the tint can still show next to a white diamond.

A well-cut diamond in a high color grade, like the E color, VS1 clarity center stones in our house rings, gives a cleaner white sparkle with less color play. That is the look most people mean when they say "it looks like a real diamond."

Moissanite is priced like a manufactured gem, not like a diamond. Prices vary by maker and cut quality, but for the same face-up size a moissanite costs a small fraction of a natural diamond and well under a lab-grown diamond. That is its whole appeal.

Here is what real diamonds cost in our showroom catalog, so you can see the other side of the comparison:

The honest takeaway: lab-grown diamond closed much of the price gap that used to make moissanite the only budget option. Lab-grown retail prices fell sharply after 2020, so a real diamond in a size that once felt out of reach is now within a few hundred to a few thousand dollars of moissanite. Read moissanite vs lab-grown diamond for that matchup in detail.

Pawn shops and buyers check stones with handheld testers. Knowing how each one behaves explains a lot of street confusion.

Because moissanite conducts heat almost like diamond, a cheap thermal pen will beep "diamond" on it. That is how a lot of buyers get fooled. A multi-tester adds an electrical check that catches moissanite. One wrinkle: a few rare natural diamonds (type IIb, the blue ones) and some lab diamonds grown with traces of boron also conduct electricity, so a single reading is never final. A trained eye with a loupe, or a lab report, settles it. See diamond certificates from GIA and IGI.

Plan on moissanite having almost no resale value. There is no organized secondhand market for it, and buyers price it as a manufactured stone. If you sell a moissanite ring, expect to be paid mostly for the gold.

Diamond resale depends on origin. Natural diamonds keep more value than lab-grown, though even natural stones sell back well below retail; the IDEX index showed natural prices down 11.5% over the 12 months to March 2026. Lab-grown diamonds, like moissanite, should be bought for wearing, not as a store of value. The gold in any piece always keeps its metal value, which is one reason we use solid 10K and 14K gold rather than plated metal.

Moissanite shows up a lot in iced-out chains, tennis pieces and pendants because it gives a big stone count for little money. If you shop that market, read the listing carefully:

• The stone must be named. "VVS moissanite" is a moissanite. VVS is a clarity grade, not a stone type.
• "Passes the diamond tester" usually means a thermal pen, which moissanite fools by design.
• The metal matters as much as the stone. Many moissanite chains are sterling silver or plated brass, not gold.

Our showroom iced pieces use real diamonds, listed as lab-grown or natural, in solid gold. Examples: the Round Lab Diamond Necklace 9.18 ct, 14K White Gold at $5,300 and the Round Lab Diamond Bracelet 7.49 ct, 10K White Gold at $2,200. See the full diamond jewelry collection.

1. "It passed the tester, so it is a diamond." A thermal pen cannot separate moissanite from diamond. Only an electrical check, a loupe or a lab can.
2. "VVS means diamond." VVS is a clarity grade. Sellers stick it on moissanite and even on cubic zirconia because buyers associate it with diamonds. Read what VVS diamonds are before you trust the label.
3. "Moissanite is a lab diamond." Both are made in a lab, but only one is diamond. A lab-grown diamond is carbon, graded on color, clarity, cut and carat like any diamond.
4. "Moissanite holds value like diamond." It does not. There is no secondhand market that pays much for it.

Use this short list for any stone you are about to buy, online or in person:

Our showroom pieces are listed with stone origin, metal and karat. Every order ships insured, and you can request a return within 7 days of receiving an item with a manufacturing defect.

If budget is the only reason you are looking at moissanite, price a lab-grown diamond first. Learn the grading basics in the diamond 4Cs guide and clarity chart, and read are lab diamonds real. Then come to the Miami showroom and put a diamond under the loupe yourself.