What Is Moissanite? Material, Size and Testing
Moissanite is silicon carbide. Most jewelry moissanite is laboratory-created. Natural and laboratory-grown diamonds have a carbon diamond structure. GIA material guide.
Is moissanite a lab-grown diamond?
No. Being grown in a laboratory does not make two materials the same. Lab-created moissanite is silicon carbide; a lab-grown diamond has diamond's carbon structure. Clear, faceted stones may look similar in a photograph, but appearance alone does not establish the material.
What gives moissanite its appearance?
Moissanite can show strong rainbow flashes as light passes through its facets. The visible effect also depends on cut, stone size, lighting and the viewing angle. A close-up photograph taken under bright lighting will look different from the same piece in soft daylight.
Moissanite is resistant to scratching, but the finished jewelry still needs care. Hardness does not mean that a gemstone, prong, silver base or plated surface cannot be damaged.
Can a diamond tester identify moissanite?
A thermal diamond tester responds to heat conduction. Moissanite can produce a diamond-like response on some thermal testers. A thermal result alone cannot distinguish moissanite from diamond.
Identification requires methods and interpretation appropriate to the stone. A jeweler or gemological laboratory can select suitable testing. A photograph of a probe, an indicator light or a beep is not a complete material identification.
Why do millimeters, carats and DEW differ?
- Millimeters (mm)
- Physical dimensions: diameter for a round stone, or length and width for an elongated shape.
- Carat (ct)
- A unit of weight. Stones of equal weight can have different face-up sizes because of their shape and cutting proportions.
- Diamond equivalent weight (DEW)
- A size comparison with diamond, rather than the moissanite's actual carat weight.
Moissanite and diamond do not have the same density, so equal dimensions do not mean equal actual weight. Read the millimeter measurements alongside the product's carat description. See the ring-size and stone-size guide for a practical on-hand comparison.
What else should I compare?
Look at the stone's shape, stated color, clarity information and cut details. Shape is the outline viewed from above. Facet arrangement, proportions and finish influence light return. Clarity describes internal and surface characteristics.
GRA moissanite grading documentation is included at no extra charge. This documentation describes the moissanite; S925 silver material testing is a separate optional service. Available on request; fees and turnaround time quoted separately. See documentation and ordering details.
For everyday wear, the metal and finish matter too. Our S925 silver, plated finishes and care guide explains the silver base, the two color-dependent finish sequences and gentle cleaning.
How do moissanite, diamond and cubic zirconia compare?
| Gem material | Composition and origin | Mohs hardness |
|---|---|---|
| Natural diamond | Carbon with a diamond crystal structure, formed in nature. | 10 |
| Laboratory-grown diamond | Carbon with a diamond crystal structure, grown in a laboratory. | 10 |
| Moissanite | Silicon carbide. The stones commonly used in jewelry are laboratory-created. | 9.25 |
| Cubic zirconia (CZ) | Laboratory-created zirconium oxide. | 8.5 |
Moissanite resists scratching more than CZ. Diamond, moissanite and CZ also differ in their optical properties. Choose the material for the appearance, wear and budget you want. GIA comparison of diamond simulants and GIA on natural and laboratory-grown diamonds.
Is moissanite suitable for an engagement ring or everyday wear?
Moissanite's scratch resistance makes it suitable for engagement jewelry. Its Mohs rating describes resistance to scratching. Resistance to chipping or breaking is a separate property, and a hard impact can still damage a stone or its setting. For regular wear, also compare the ring's construction, stone protection and metal. Inspect prongs and clasps and follow the care instructions for the silver and plated finish. GIA explains hardness, toughness and stability.
What if moissanite looks cloudy or yellow?
Check a clean stone in neutral lighting before judging a change. Surface deposits can reduce sparkle. Moissanite's double refraction can also make internal facet images look less sharp, and some stones show a yellow or gray tint at certain angles. These effects need to be distinguished from damage or a permanent color change. If gentle cleaning does not resolve a new change, ask a jeweler to inspect the piece. For a colored or treated stone, ask about the treatment and its care requirements. GIA on moissanite's appearance and GIA on cleaning and treated gems.
Which shape looks most like diamond?
Compare the shape together with the cut, dimensions and lighting. Moissanite has stronger rainbow fire than diamond, which can be more noticeable in larger stones. Compare the actual stone's facet pattern and appearance in daylight as well as bright spot lighting. Choose a shape and level of fire you enjoy. GIA explains moissanite's fire and double refraction.
What does 1-carat DEW look like in millimeters?
As an example, Charles & Colvard compares a 6.5 mm round diamond weighing about 1.00 ct with a 6.5 mm round moissanite weighing about 0.88 ct. The visible diameter is the same, while the actual weights differ. The relationship varies with shape and cutting proportions. Use the dimensions of the selected product option. Charles & Colvard explains millimeters and diamond-equivalent weight.
What do D color and VVS1 mean on a moissanite listing?
These labels use diamond-grading terminology. On GIA's diamond color scale, D is the colorless end. VVS means Very, Very Slightly Included. VVS1 describes inclusions that are extremely difficult for a skilled grader to find at 10× magnification. For moissanite, read the seller's stated grading method and the accompanying report. Confirm the grading method, examiner and match to the supplied stone for the order. GIA diamond color terminology and GIA VVS clarity terminology.
For the included GRA document, check the issuer, report number, stone dimensions and correspondence with your order. Read the document scope and product-verification steps.
How should I compare the price of a 1-carat moissanite silver ring?
First confirm whether “1 carat” describes actual stone weight or diamond-equivalent size. Compare millimeter dimensions, shape and cut, the complete setting, silver construction, finish, included documents, shipping and return terms. For a current FUGUI price, choose the exact options on the Six-Prong Moissanite Solitaire Ring or another product page. The selected option's price is the price to use in your comparison. FTC gemstone buying guidance.
Does moissanite jewelry hold its resale value?
A future resale offer depends on the piece, condition, demand and the buyer. If resale matters to you, seek current offers for the specific piece and account for selling fees and shipping. Ask for any proposed buyback terms in writing before relying on them. GIA explains fair-market-value appraisal and selling jewelry.