Mastering the Rapaport Matrix

The Rapaport Price List, established in 1978, is the international benchmark used by diamond dealers to establish wholesale prices. It is heavily protected, updated weekly, and operates as a standardized matrix rather than a consumer catalog.

The Wholesale "Back"

In the diamond industry, stones almost exclusively trade at a discount to the Rapaport list price, colloquially known as "the back." A stone trading at "-30%" means the buyer pays 30% less than the matrix value. The magnitude of this discount varies daily based on global supply, market liquidity, and the specific desirability of the stone's grading report.

Premium Market Conditions

While discounts are standard, exceptional stones—such as a D-Flawless with "Triple Excellent" cut parameters and zero fluorescence—may trade at a premium above Rapaport (+5% to +10%). This also occurs during extreme market shortages or when certain magic sizes experience sudden spikes in retail demand.

Deep Dive into the GIA 4 Cs

The Gemological Institute of America (GIA) established the globally accepted "4 Cs" to objectively evaluate a diamond. A shift in just one micro-grade can swing a diamond's wholesale valuation by thousands of dollars.

✓ Weight & Color Matrices

Carat (Weight): Carat is a measure of mass (1 carat = 0.2 grams), not physical dimensions. The Rapaport grid separates pricing into distinct weight brackets. Crossing a "magic size" threshold (e.g., from 0.99ct to 1.00ct) triggers a massive, non-linear price jump.

Color (Hue): Graded on an alphabetical scale from D (absolutely colorless) to Z (light yellow/brown). D, E, and F are the ultra-premium "Colorless" grades, while G, H, I, and J represent "Near Colorless," offering the best value for consumer jewelry.

✓ Clarity & Cut Precision

Clarity (Inclusions): Measures internal flaws under 10x magnification. Ranges from Flawless (FL) to Included (I3). VVS (Very Very Slightly Included) and VS (Very Slightly Included) stones appear flawless to the naked eye.

Cut (Proportions): Exclusively applied to Round Brilliant diamonds. Cut dictates light performance—brilliance (white light), fire (colored flashes), and scintillation (sparkle). An Excellent cut commands a heavy premium over a Good cut, regardless of color or clarity.

Precious Metal Metallurgy & Scrap

Fine jewelry is rarely crafted from 100% pure elemental metal. Pure gold (24K) and fine silver (99.9%) are too malleable and prone to scratching for daily wear. Jewelers introduce alloy metals (like copper, zinc, or palladium) to increase tensile strength and alter the color (e.g., Rose Gold or White Gold). Therefore, calculating accurate melt value requires extracting the exact pure metal weight from the alloyed mass.

Gold Karat Percentages

The Karat system measures gold purity out of 24 parts:

24K: 99.9% Pure (24/24)
22K: 91.6% Pure (22/24)
18K: 75.0% Pure (18/24)
14K: 58.3% Pure (14/24)
10K: 41.7% Pure (10/24)

Silver & Platinum Fineness

Unlike gold, silver and platinum use the millesimal fineness system (parts per thousand). "Sterling Silver" is stamped 925, denoting 92.5% purity. Platinum jewelry is typically stamped 950 (95% pure) or 900 (90% pure), requiring less alloying due to platinum's inherent extreme density and durability.

The Rapaport Pricing Methodology

The diamond industry does not price stones linearly based on weight. Instead, wholesale trading relies on the Rapaport Price List, which cross-references a diamond's carat weight bracket, color grade (D-Z), and clarity grade (IF-I3) to establish a baseline price per carat.

Because the Rapaport list serves as a high benchmark, dealers trade stones at a discount or premium to the list price. Our calculator allows jewelers and consumers to instantly apply market discounts (e.g., -15% off Rap) to arrive at the true wholesale or retail valuation of a stone.

Precious Metals Valuation

Karat Purity: Gold is alloyed for strength. 24K is 99.9% pure, 18K is 75% pure (18/24), and 14K is 58.3% pure. Scrap gold valuation heavily depends on the day's spot price multiplied by the exact purity percentage.
Troy Ounces vs Grams: Precious metals are weighed in Troy Ounces, not standard (Avoirdupois) ounces. 1 Troy Ounce = exactly 31.1034768 grams. Our calculators automatically handle this vital conversion factor to prevent valuation errors.

Diamond & Jewelry Calculators

Pricing Breakdown

Melt Value Details

The Ultimate Guide to Jewelry Appraisals