TL;DR: Two quotes for what looks like the same diamond can differ significantly once you account for certification lab, exact cut proportions, and what's actually included in the price. Compare like for like on the certificate itself before comparing the final number.
Why Two Quotes Rarely Compare as Simply as They Look
A quote showing carat, colour, and clarity looks like enough information to compare directly against another quote with the same three figures. In practice, several things can differ beneath that surface-level match, and they can add up to a genuinely different stone and a genuinely different price for reasons that aren't obvious from the headline numbers alone.
Check the Certification Lab
GIA and IGI are both reputable, but grading standards aren't perfectly identical between labs — see our GIA vs IGI guide for the detail. A stone graded G/VS2 by one lab isn't automatically identical in appearance to another stone graded G/VS2 by a different lab. When comparing two quotes, confirm both certificates are from labs you consider comparable before treating the grades as directly equivalent.
Check the Actual Cut Proportions, Not Just the Grade
Cut grade for a round brilliant is standardised, but for fancy shapes there's no equivalent grade — two ovals both described as "excellent cut" by different sellers can have meaningfully different proportions, and proportions affect how the stone actually looks far more than colour or clarity do. Ask for the certificate itself, not just a summary, and compare table percentage, depth percentage, and length-to-width ratio directly.
Check What's Actually Included
Setting cost, hallmarking, insurance during production, and delivery aren't always itemised the same way between two quotes — one quote might already include costs the other lists separately, which can make an apparently cheaper quote less of a genuine saving once everything is accounted for.
Ask to See the Actual Certificate
A genuine grading certificate includes a plot of inclusions, exact measurements, and a laser inscription number you can independently verify against the issuing lab's database. Any seller unwilling to provide the actual certificate, rather than just a summary of its headline figures, is worth treating with more caution than one who provides it readily.
Comparing Quotes at À Vie Diamonds
We're happy to talk through a quote you've received elsewhere and help you understand exactly what it does and doesn't include. Get in touch for an honest second opinion.
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Frequently Asked Questions
Why do two quotes for the same specification differ so much in price? Certification lab, exact cut proportions beyond the headline grade, and what's included in the price (setting, hallmarking, delivery) can all differ even when carat, colour, and clarity look identical on paper.
Should I ask to see the actual diamond certificate? Yes — a genuine certificate lets you compare exact proportions and verify the stone independently, rather than relying on a seller's summary of the headline figures.
Last reviewed: July 2026 · À Vie Diamonds