Built by gemologists, tired of the guesswork
Diamonds Tester began with a simple frustration: a 20-dollar tester pen calls moissanite a diamond, and the jeweller down the road wants a fortune just to tell you what you already own. We thought owners deserved an answer that was independent, instrument-backed and free of anyone’s sales target.
An answer you can actually trust
After years inside the trade, our founders watched the same scene play out again and again — an inherited ring with no paperwork, a private-sale stone that looked too good, a tester pen confidently lighting up green on a piece of moissanite. The tools people relied on were either too cheap to be honest or too expensive to be accessible.
So we built the lab we wished existed: gemologist-grade testing that meets you where you are. Snap a photo for a free first-pass verdict, or send your stone in an insured mailer for a full, certificate-ready report. Same rigour either way — and never a reason to inflate your stone’s value, because we don’t sell diamonds.
No markup
We test stones, we don’t trade them.
Certified team
GIA & IGI gemologists on every report.
Simulant-proof
Electrical staging catches moissanite.
Private by default
Your photos and stones, never shared.
How we reach a verdict
Four layers of evidence stack into every result — from a quick optical read to full spectroscopy — and a human gemologist has the final word.
Optical benchmarking
Brilliance, dispersion and facet geometry read from your photos and scored against a library of GIA-graded reference diamonds.
Conductivity staging
Thermal and electrical probes separate diamond from moissanite — the single test cheap pens get wrong every time.
Spectroscopy & fluorescence
FTIR and UV imaging reveal the growth signatures that distinguish natural, HPHT and CVD lab-grown diamonds.
Gemologist review
No certificate ships on a machine reading alone. A certified gemologist signs off on origin, treatment and the full 4Cs.
The principles behind every report
Honest before flattering
If your stone is lab-grown, a simulant, or worth less than you hoped, we say so plainly. A straight answer is the whole product.
Evidence over opinion
Every verdict traces back to a measurable tell — conductivity, refractive index, spectroscopy or benchmarked optics — not a salesperson’s hunch.
No markup, no theatre
We don’t sell diamonds, so we have no reason to talk yours up or down. You pay for the test, never for an agenda.
Your stone, your data
Photos and samples are never sold or shared. Lab pieces are insured and tracked from the moment they leave your hands.
The people who sign your report
Credentialed, independent and accountable. Every verdict carries a name.
Dr. Helena Voss
Founder & Chief Gemologist
Spent twelve years grading for an Antwerp trading house before founding Diamonds Tester. Helena built our optical benchmarking framework against thousands of GIA-graded reference stones.
Nathan Cole
Head of Laboratory
Runs the instrument floor — conductivity staging, FTIR and UV fluorescence. Nathan’s protocols are why a moissanite has never once slipped past a Diamonds Tester lab report.
Amara Okafor
Senior Gemologist, Origin & Treatment
Specialises in separating natural from lab-grown and detecting HPHT treatment. Amara reviews every borderline origin call before it reaches a certificate.
Tomás Reyes
Lead, Photo Verification
Trains and audits the model that powers our instant photo screen, calibrating it stone-by-stone against the lab’s graded outcomes.
Ready for an answer you can trust?
Start with a free photo screen or send your stone to the lab. Either way, a certified gemologist stands behind the result.