The SHEER Standard
Five criteria. One standard. Independently graded.
Most moissanite is sold without independent certification. The stone arrives with a generic GRA report, an in-house certificate, or no documentation at all — and the buyer is asked to take the seller's word for the quality.
SheerGem is built on the opposite assumption: that you shouldn't have to take our word for anything.
Every stone we ship is independently graded by the International Gemological Institute — the same lab that certifies fine diamonds — against a five-criteria standard called SHEER. Less than 10% of the moissanite available today meets it. This page explains what the standard tests, why each criterion matters, and how to verify any SheerGem stone yourself.
Why IGI
The International Gemological Institute has been grading gemstones since 1975. They operate fourteen laboratories across the world, employ over 1,000 gemologists, and issue certificates that are accepted as authoritative by the global jewelry trade.
We chose IGI for one reason: when you buy a fine diamond, the certificate that comes with it almost certainly comes from IGI, GIA, or AGS. By submitting our moissanite to the same laboratory that grades fine diamonds, we put our stones in the same evaluation framework as the most rigorously certified gems in the world.
The contrast is the point. Most moissanite is graded by GRA — a lab whose certificates the industry doesn't widely trust. Some brands grade in-house, which is to say they grade themselves. We submit to a third party with a fifty-year reputation. The certificate isn't marketing. It's verification.
The five criteria
SHEER is an acronym. Each letter represents a criterion that every SheerGem stone must pass to earn certification. A stone that fails any one criterion is rejected — we don't grade on a curve and we don't ship near-misses.
S — Superior cut
Cut is the criterion that determines how a stone interacts with light. Excellent cut maximizes brilliance and fire; poor cut produces a stone that looks dull regardless of its other qualities. SheerGem requires Excellent grades on cut, polish, and symmetry — the same top-tier benchmarks used in fine diamond grading. Cuts are evaluated by IGI gemologists using calibrated equipment, not by visual estimation.
H — Hueless halation
Halation refers to the way a stone disperses colored light around its facets. In poorly graded moissanite, halation produces visible green or yellow tints that diminish the stone's apparent purity. Hueless halation means the stone disperses light cleanly, without color cast. This is the criterion that most often disqualifies moissanite from the SHEER standard.
E — Exceptional fire and brilliance
Moissanite has a higher refractive index (2.65–2.69) and dispersion (.104) than diamond — meaning it can produce more fire and brilliance than diamond when properly cut. The "can" matters. Most moissanite never realizes that potential because of inferior cut or symmetry. SheerGem stones must demonstrate measurable fire and brilliance at the top of moissanite's optical range.
E — Ethically sustainable
Every SheerGem stone is laboratory-grown — zero mining, zero environmental disruption from extraction, zero ambiguity about origin. Lab-grown moissanite is fully traceable from synthesis to setting. We require sourcing documentation from every supplier and only work with labs whose practices we've verified.
R — Risk-free guarantee
Every SheerGem stone is backed by the SheerPromise: a lifetime warranty against any damage, lifetime trade-up credit, lifetime cleaning and inspection, and a one-year return window. The R in SHEER reflects a position we hold: a stone isn't truly graded until the seller stands behind it for the life of the piece.
What you'll receive
Every SheerGem piece ships with the IGI report for its stone. The report includes the carat weight, measurements, cut grade, polish grade, symmetry grade, refractive index, dispersion value, and a unique report number that you can verify on IGI.org.
The report arrives twice: once as a physical document in your box, and once digitally in your order confirmation email. You can keep the physical report for insurance documentation and reference the digital version any time.
How to verify
Every IGI report has a unique number printed on it. To verify any SheerGem stone:
Visit IGI.org and use their report verification tool. Enter the report number from your certificate. The tool will confirm the report's authenticity and display the same grading information that appears on your physical certificate.
This verification is independent of us. We have no ability to alter or influence what the IGI verification tool returns. If a SheerGem report number doesn't verify on IGI.org, the stone isn't real — contact us immediately.
What we won't do
We won't issue our own certificates. The credibility of grading depends on independence from the seller, and any certificate written by us about our own stones would defeat the purpose of certification.
We won't grade on a curve. A stone either meets all five SHEER criteria or it doesn't enter our inventory. We don't have a "SHEER Plus" or a "Standard SHEER" tier — we have one standard, and the stone passes or it's rejected.
We won't lower the standard to expand inventory. As demand grows, the easy move is to soften the criteria so more stones qualify. We won't. The standard is what makes the brand the brand.
Questions
If you have questions about the SHEER standard, the IGI relationship, or how to verify any specific stone, email us at hello@sheergem.com. We'll answer.