How We Rank

Independence First

Our business model is deliberately simple: users who want full access pay us for a pass. We do not accept affiliate commissions, referral fees, click revenue, or any other payment from the retailers whose diamonds we list. No retailer pays for placement, inclusion, a ranking boost, a logo position, or favourable scoring.

This is a core part of our value proposition. If we ever introduce a revenue stream that involves retailer payments, we will disclose it on this page and in our Terms of Service before it takes effect, and we will label the affected results clearly.

Retailer Inclusion

We include online diamond retailers that publish machine-readable inventory and certified diamond data at commercial scale. Inclusion is not negotiable and is not related to any commercial relationship with us. We currently track 100+ retailers across 15+ countries.

A retailer may be excluded or paused if we detect persistent price inaccuracy, fabricated certification references, or systematic attempts to block price transparency. We document any such decision on a case-by-case basis and are willing to re-include a retailer once the issue is resolved.

The Caratlytics Score

Every diamond in our database is evaluated by the Caratlytics scoring system. The overall score (0 to 100) combines four components:

• Quality 35%. Pure gemological quality: cut, polish, symmetry, fluorescence, proportions (table and depth), and girdle.
• Value 30%. Price relative to comparable diamonds (same shape, carat band, colour, clarity, and origin).
• Certification 20%. Grading laboratory strength and credibility (GIA, IGI, HRD, and others) weighted by market acceptance.
• Market 15%. Market position: how the listing compares against peer baselines and historical price movement.

The methodology is documented in our Terms of Service and may be refined as we improve it. We will not change the weightings in a way that advantages any retailer or commercial partner.

Default Sort Order

The default sort order in the diamond explorer and in Lucy's recommendations is overall Caratlytics score, descending. This is followed by retailer diversity as a secondary key, so equally scoring diamonds from different retailers interleave rather than clumping.

Users can choose a different sort (lowest price, pure quality, newest listings, largest discount, and so on). No sort option is weighted in favour of any retailer.

Data Freshness

Diamond inventory and prices are refreshed on a per-retailer schedule. Large retailers are refreshed multiple times per day; smaller retailers at least daily. Listings older than 14 days are automatically marked as sold or removed.

Each listing page shows the last-seen timestamp. Despite this, retailer sites are the source of truth: verify price and availability before purchase.

Disputes

If you are a retailer and you believe a listing of yours is shown incorrectly, contact us at [email protected] with the listing URL and the correct information. We will investigate and correct verified errors.

If you are a consumer and you believe a score, match, or comparison is wrong, use the feedback link on any diamond page. We review feedback weekly.

Limitations and known gaps

The Caratlytics Score and the cross-retailer matching that powers it both have known limitations. We disclose them rather than paper over them.

Sample thinness in rare categories. Fancy-color diamonds, very high carat sizes (over 5ct), and stones from boutique retailers we do not yet index can produce scores calibrated against a smaller cohort than the headline figure. We surface this on individual diamond pages where the subscore confidence is low, but it is worth knowing in aggregate.

Listing prices are not transaction prices. Especially above USD 10,000, retailers negotiate. Our index sees the listed price, not the closed price. Our spread numbers are therefore an upper bound on what most buyers actually pay.

Cross-retailer match coverage. Some retailers redact certificate numbers or use proprietary SKUs in ways that prevent matching. Approximately 4.29 million stones in our index appear at only one retailer right now. Some are truly single-source; others are matchable but redacted.

Service-vs-stone separation. The score evaluates the stone and the price, not the retailer experience. A higher-priced listing at a retailer with a generous return window may genuinely be the right purchase for some buyers. We rank stones; service evaluation is yours to make.

Editorial process

Carat Hunter editorial content is published under the Lucy byline. Lucy is AI, working from our index of over 17 million certified diamond listings across more than 100 retailers. The pipeline runs cohort queries, surfaces patterns in the data, and drafts prose.

Pieces run through automated checks before publication. When we find an error after a piece is live, we correct it in place and add a dated entry to the corrections log below.

Cert numbers cited as anchors are real, active, and verifiable on the issuing lab's public report-check service. GIA, IGI, HRD, and AGS are the labs we cite for grading framework authority.

Our scoring logic is grounded in this editorial analysis. The cross-retailer pricing analysis establishes the spread distribution behind the Value and Market subscores. See all editorial analysis →

Corrections log

When we identify an error in a published piece or methodology claim, we correct it in place and add a dated entry here. Substantive corrections include changes to numerical findings, cohort sizes, or stated conclusions. Typo and prose fixes do not appear here.

No corrections logged to date. Last reviewed May 9, 2026.