Last updated: October 2026
By Jack Lv, General Manager — 925 sterling silver and GRA moissanite manufacturing in Foshan since 2011
A certificate does not make a stone more valuable on its own; it makes your claim about the stone checkable, and checkable claims are what support a higher retail price. For moissanite the routine document is a GRA report, normally one report per stone, while IGI and GIA are diamond laboratories whose grading scales were built for diamonds, and GIA does not issue grading reports for moissanite.
They are three different things: a GRA report is the certificate format most often attached to moissanite in the wholesale trade, while IGI and GIA are diamond laboratories whose scales and report layouts were designed for diamonds and lab-grown diamonds. GIA does not grade moissanite at all.
GRA reports are the certificate format most often attached to moissanite in the wholesale trade: a card or report, usually one per stone, carrying a reference number and describing the stone in the four-C language of colour, clarity, cut and carat weight.
IGI and GIA are the two best-known gem laboratories in the diamond business. Their grading scales and report layouts were designed for diamonds and lab-grown diamonds, and that is how their reports should be read. GIA does not grade moissanite: there is no GIA grading report for a moissanite stone, so any listing claiming one is simply wrong. IGI's publication work likewise centres on diamonds and lab-grown diamonds.
So a supplier presenting a diamond-laboratory document as the proof behind a moissanite order is either confusing material identification with grading or misrepresenting the paperwork. Ask what the document covers, who issued it, and what the reference number resolves to before you repeat any claim to your own customers.
| Document | Issued for | What it records | Where buyers meet it |
|---|---|---|---|
| GRA report | Moissanite | A description of the individual stone plus a reference number; normally one report per stone | Wholesale and retail moissanite |
| IGI report | Diamonds and lab-grown diamonds | Diamond grading: colour, clarity, cut, carat, measurements, plot | Loose natural and lab-grown diamond trade |
| GIA report | Diamonds | Diamond grading on the GIA scale | Loose diamond trade; not issued for moissanite |
| Independent material identification | Any stone | States what the material is, for example silicon carbide, rather than grading quality | Disputes, high-value parcels, buyer-specified testing |
A grading report answers how good a stone is; an identification report answers what the stone is. For moissanite the second question is the one that protects you, because the real risk is receiving cubic zirconia, glass or a coated imitation instead of silicon carbide — 9.25 on the Mohs scale against 8 to 8.5 for CZ.
A grading report answers how good a stone is. An identification report answers what the stone is. For moissanite the second question protects you, because your real risk is not a slightly warmer stone, it is receiving cubic zirconia, glass or a coated imitation instead of silicon carbide.
Moissanite is silicon carbide (SiC) and cubic zirconia is zirconium dioxide (ZrO2). The two look similar in a photograph, but they are different materials with different hardness: moissanite sits at 9.25 on the Mohs scale, against 8 to 8.5 for CZ and 10 for diamond. If an order value justifies it, ask for a material test on a sample drawn from the production batch, not only on the stone that was photographed for the listing.
There is no honest single number, because the gap depends on your channel. What stays constant is the mechanism: a documented stone lets a seller make a specific, verifiable promise instead of a vague one, and that removes doubt at the moment the customer decides.
There is no honest single number here, because the gap depends on your channel. What stays consistent is the mechanism: a documented stone lets a seller make a specific, verifiable promise instead of a vague one, and that removes doubt at the moment the customer decides.
In practice, an identical setting holding a documented stone generally supports a higher list price than the same setting with an undocumented stone. The premium tends to be larger where the customer cannot inspect the stone in person, such as marketplaces, own-brand e-commerce and social selling, than behind a counter where the stone is in hand. Certification also changes what a return looks like: when the claim is written down and verifiable, a dispute becomes a lookup rather than an argument.
Check the number at its source rather than looking at the card: a real report can be looked up with the issuing body. If the number cannot be found independently, treat the document as a claim rather than evidence.
Decide per range rather than per company: certification protects high-value pieces and marketplace listings, and adds cost where nobody will ask. The mistake in both directions is applying one rule to every order.
A reference number is content: it belongs on the product page, the care card, the packaging insert and in the answer to the question every buyer eventually asks, how do I know this is really moissanite. Two disciplines make it work — keep the numbering consistent between what you advertise and what you ship, and never imply a laboratory status you do not hold.
The most common mistake is treating certification as a line item to be minimised. A reference number is content: it belongs on the product page, the care card, the packaging insert and in the reply to the question every buyer eventually asks, which is how do I know this is really moissanite.
Two disciplines make that work. Keep the numbering consistent between what you advertise and what you ship, and never let a listing imply a diamond-laboratory status you do not hold. A verifiable GRA report per stone plus an honest description of what the report covers will outperform an inflated claim the first time a customer tests it.
No. A GRA report is a moissanite-focused document, normally issued one per stone. A GIA report is a diamond grading report, and GIA does not grade moissanite. Treating the two as interchangeable in your marketing copy creates a disclosure problem the first time a customer checks.
Any printed document can be copied, so a card on its own is not proof. Verify the reference number through the issuer's own lookup, match it to the physical stone, and test a sample independently on larger orders.
A certificate documents a claim about the stone; the proof is an identification test. For most retail orders the document is enough, but on a dispute or high-value parcel ask for a material test on the actual batch.
No. Single-stone and bridal pieces justify one report per piece, while multi-stone and pave orders usually do not. Decide per SKU before you quote the range, so certification cost sits in the right price points.
It supports a higher price because the claim becomes checkable, and it turns a potential return into a lookup. How much more depends on your channel and on whether your customers can physically inspect the stone.
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