FACETWIREPrice IntelligenceHow Facet Wire matches diamonds
Facet Wire compares diamond prices across retailers. A comparison is only useful if it is honest, so here are the exact rules every match, gap and certificate page on this site follows — no estimates, no invented history.
The matching rules
- Identical shape, color and clarity. A pear is only compared with a pear, an E color only with an E, a VVS2 only with a VVS2.
- Carat within 0.10. The two stones' weights may differ by at most a tenth of a carat, so per-carat math stays meaningful.
- Lab-grown is never compared with natural. They are different markets with different prices; mixing them would manufacture fake gaps.
- Different retailers only. A spec match is always across two stores — that is where the price gap lives.
- Each listing is used once in the nightly gap ranking, so one cheap stone cannot star in five different "deals".
- Same-stone claims need the certificate. Two listings are called the same physical stone only when the grading lab and certificate number match exactly. Everything else is labeled a spec match — same grades, different stone.
What Facet Wire tracks
Right now Facet Wire tracks 2,149 live listings across 10 retailers (Blue Nile, Frank Darling, With Clarity, MiaDonna, Ritani, Ada Diamonds, Brian Gavin Diamonds, Friendly Diamonds, VRAI, Whiteflash), and 1,454 of those listings publish a certificate number. Prices refresh nightly; every page is rebuilt from the latest scrape. Facet Wire began tracking in October 2026 — its price history starts there and grows daily. We never backfill, estimate or invent older prices.
The honest limitations
- A spec match is not the same physical diamond, and we never present it as one. Cut quality, fluorescence and proportions can differ between two stones with identical headline grades.
- Certificate numbers are only visible for part of the market — some retailers never publish them, so same-stone tracking covers the 1,454 listings that do.
- A listed price is the retailer's price when we scraped it. Stones sell and prices change; the retailer's own page is the final word at checkout.
- Facet Wire is a price tracker, not a gemologist. We compare prices and grades as published — we do not grade stones ourselves.
Frequently asked questions
What counts as a match on Facet Wire?
Two listings match when they describe the same kind of stone: identical shape, color and clarity, carat weights within 0.10 carats of each other, and the same origin — lab-grown is only ever compared with lab-grown, natural only with natural.
Does a match mean it is the same physical diamond?
No. Spec-matched listings are different stones with identical grades, unless the certificate number matches — a matching lab and certificate number is the only proof two listings are the same physical stone.
How fresh is the data?
Facet Wire re-scrapes its retailers nightly and rebuilds every page from the fresh data. Facet Wire began tracking prices in October 2026, and its history grows from there — nothing is backfilled or estimated.
Why do prices differ so much for identical specs?
Each retailer sets its own markup, and most shoppers only check one or two stores. Identical grades leave the retailer's service and pricing strategy as the only differences — the gap between them is what Facet Wire exists to show.