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Open standardMethodology v1.0Eff. 2026-05-09

The diamond market, measured.

Caratlytics publishes the methodology, the grade scale and the price index behind the Caratlytics Score: a single 0 to 100 measure of a diamond's quality, value, certification and market position, computed for every certified stone we observe across more than one hundred retailers.

Example score · GIA stone
A
Score 94 / 100
Quality96
Value91
Certification98
Market88
0
retailers monitored
0
active listings
0
certified diamonds
0
diamonds matched across retailers
§ 01
The methodology

Four pillars, one score.

Every Caratlytics Score is a weighted composite of four published sub-scores. No hidden factors, no paid placement, no retailer input.

Overall = Quality × 0.35 + Value × 0.30 + Certification × 0.20 + Market × 0.15
35%
Quality
Gemological merit: cut, color, clarity, proportions, finish and fluorescence, graded against published tables.
30%
Value
Price positioning: where the stone's price per carat sits against the statistical baseline for its category.
20%
Certification
Trust: which laboratory graded the stone, how complete its data is, and whether the certificate checks out.
15%
Market
Market intelligence: cross-retailer verification, 30 day price trend, stability and savings potential.
§ 02
The grade scale

The grade scale

Scores map to six consumer grades. The bands are fixed, published and identical everywhere the score appears.

A+
90 to 100
Exceptional
A
80 to 89
Excellent
B+
70 to 79
Very Good
B
60 to 69
Good
C
50 to 59
Average
D
0 to 49
Below Average
§ 03
Caratlytics Diamond Price Index · May 2026

Retail diamond prices, monthly.

A monthly, openly licensed index of retail diamond prices: median USD per carat for natural and lab-grown diamonds, computed from a systematic sample of millions of listings.

Natural · median / ct
$2,253
▼ -0.26% MoM
Lab-grown · median / ct
$505
▼ -7.52% MoM
Overall · median / ct
$758
▼ -13.53% MoM
Natural
Lab-grown
Dec ’25Jan ’26Feb ’26Mar ’26Apr ’26May ’26Jun ’26

Sample: systematic 1 in 10 of listings, each contributing its most recent observed price in the calendar month. Unit: USD per carat under pinned conversion rates, so the series moves when retailers reprice, never on currency fluctuations. Series begins December 2025; releases are immutable once published.

§ 04
Why a standards site

Grading tells you what a stone is. It does not tell you whether the price is fair.

Diamond grading does not tell you whether the same certificate is listed cheaper elsewhere, or whether a retailer's data can be trusted. The Caratlytics Score adds that market layer, and this site is its public record.

Caratlytics is developed by the team behind Carat Hunter, the diamond search engine where the score is applied to live inventory. We publish the full methodology so anyone can inspect it, challenge it and hold us to it.

Read our governance and disclosure →

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