Premium-vs-Grid
Premium-vs-Grid
The Rapaport-relative pricing convention that dominates wholesale diamond trade
Premium-vs-grid is the diamond-trade pricing convention in which a stone is offered at a percentage above or below the baseline price published in a recognised industry price grid — most commonly the Rapaport Price List, sometimes augmented by GemGuide or IDEX — for the same weight, colour, and clarity. A diamond listed at Rap +20% commands twenty per cent above the grid figure for its grade combination; a stone at Rap −15% trades at fifteen per cent below the grid. The convention is the operative framework for almost all wholesale diamond pricing in the modern trade and is the principal way dealers communicate value on a per-stone basis.
The Rapaport reference
The Rapaport Price List, published weekly by the Rapaport Group since 1978, sets out asking prices in dollars per carat for round brilliants and pear shapes across the standard colour and clarity grades, organised by weight band. The list is widely subscribed to by dealers, retailers, and grading professionals and serves as the de facto wholesale reference for the round-brilliant diamond market. Rapaport publishes a separate list for fancy shapes other than pears, but the round and pear grids carry the strongest dealer use.
The grid is a list of asking prices, not transaction prices. The actual market price for any specific stone is set by the premium or discount applied at sale, which captures the difference between the standardised grade reference and the specific stone's quality, character, and desirability. A grid figure of $7,500 per carat for a 1.50-carat G/VS1 stone is a starting point; the transaction price depends on the cut, the specific certification body, the polish, the symmetry, the fluorescence, and the broader market conditions for stones of that profile.
What the premium captures
Diamonds at the top of the grade grid — D/IF, D/FL, D/VVS1 — typically trade at substantial premiums to the grid figure, often Rap +25 to +50 per cent or more, reflecting both the rarity of the grade combination and the demand for top-tier stones. Ideal-cut and Excellent-cut grades support meaningful premiums even at less rarefied colour-clarity combinations, particularly where GIA Excellent / Excellent / Excellent (3X) grading is documented. GIA reports themselves command a premium over EGL and other secondary laboratories: a stone with the same nominal grades from EGL trades at a substantial discount to its GIA-graded equivalent.
Beyond the standard grading variables, premiums attach to provenance (Premier Mine Type IIa, Golconda historical), to fluorescence character (none preferred for the top colour grades; faint or medium acceptable below), and to the absence of treatment indicators on the report. Premium structures change with market conditions; in soft markets, even top-grade stones trade closer to grid, and in strong markets the premium structure widens.
What the discount captures
Discounts to the grid apply to stones with characteristics that the market reads as inferior within their nominal grade. Strong fluorescence in the top colour grades produces a meaningful discount because the trade reads it as a colour and transparency concern. Modest cut grades — Good or Fair from GIA, or unknown cut from non-GIA reports — produce significant discounts. Inclusions visible to the unaided eye in stones nominally graded SI1 or SI2 produce eye-clean-vs-not-eye-clean discounts within the grade. Older reports with stale or non-current grade definitions trade at a discount to recent equivalents.
Wholesale and retail use
Wholesale dealers communicate prices in Rap-percentage terms as standard practice. A buyer asking at what Rap? is asking for the discount or premium applied to the grid for that stone. Retail jewellers translate the wholesale Rap-relative figure into a marked-up retail price, with the markup varying by retailer model. Independent jewellers tend to apply lower percentage markups on a smaller customer base; chain retailers apply higher markups on greater volume. The end-customer rarely sees the underlying Rap percentage but the trade-side mechanics are unchanged.
In the trade
Premium-vs-grid is the daily working language of the wholesale diamond trade. A dealer asking after a 1.50 G/VS1 receives quotes in Rap percentage terms, compares them across multiple sources in seconds, and selects on the combined basis of grade, percentage to grid, certification body, and stone-specific characteristics. The convention persists because it works: the grid provides a consistent reference, the premium-or-discount captures the variable, and the trade can communicate price across regions and time zones in a single shared shorthand.