Published by Prodiam Trading CC · South African diamond education

4 4Cs.co.zaThe Light Study

How pricing works

Every diamond has a trade price before it has a retail price.

Most South African buyers only ever see the retail price in a shop window. Behind that number is a wholesale price the trade works from, anchored to an international list called the Rapaport. Understanding how the trade prices a stone is the single best way to know whether you are paying a fair number or a brand premium.

Reviewed under the Light Study method · May 2026

High-key studio photograph: loose diamonds scattered on white acrylic
Exhibit · Wholesale price
VerifyReport, inscription, measurements
InspectLight return, tint, inclusions
CompareCut, colour, clarity, carat together
RouteBuy, sell, insure, or value differently

Short answer

Every diamond has a trade price before it has a retail price.

Most South African buyers only ever see the retail price in a shop window. Behind that number is a wholesale price the trade works from, anchored to an international list called the Rapaport. Understanding how the trade prices a stone is the single best way to know whether you are paying a fair number or a brand premium.

Use this rule

Do not judge one C alone. Read the certificate, inspect the actual stone, then decide whether beauty, budget, or resale confidence matters most.

What the Rapaport list is

The Rapaport Price List (the RAP) is a weekly benchmark of polished diamond prices, broken down by shape, carat band, colour, and clarity. The trade quotes against it. A stone is rarely sold at full RAP. It is sold at a discount or premium expressed as RAP-minus or RAP-plus. A dealer saying minus 30 means 30 percent below the list price for that exact spec.

What RAP-minus means for you

RAP-minus is where the real negotiation lives. Two diamonds with the same certificate can trade at very different discounts based on cut make, fluorescence, and how liquid the stone is. A retailer buys at a RAP-minus, then sells to the public at or above full RAP plus margin. A manufacturer-direct seller can pass more of the RAP-minus to you, which is why the same certified stone can land 30 to 50 percent cheaper.

Why retail prices are higher

Retail price is not only the diamond. It carries shop rent, staff, stock financing, marketing, and brand margin. None of that changes the stone in the ring. When you buy from a cutting works rather than a chain, you strip out most of those layers and pay closer to the trade number.

How to use this when buying

Get the full certificate spec first (shape, carat, colour, clarity, cut). Then ask any seller for the loose-stone price separated from the setting. Prodiam, as the direct face of a cutting works, prices from the trade side rather than the mall side, so you can sense-check a retail quote against a manufacturer-direct one for the same GIA spec.

Decision table

Use the details, not a shortcut.

TermWhat it meansWhy it matters to a buyer
RAPFull Rapaport list price for a specThe ceiling reference, rarely the real price
RAP-minus 20 to 4020 to 40 percent below listTypical trade range for a sound stone
Retail mark-upRAP plus brand marginWhat you avoid buying manufacturer-direct

Direct answers

Common questions

What is the Rapaport price list?

It is a weekly international benchmark of polished diamond prices by shape, carat, colour, and clarity. The trade quotes stones as a discount or premium to it, known as RAP-minus or RAP-plus.

Can a member of the public see Rapaport prices?

The full list is a paid trade subscription, but you do not need it. Ask a manufacturer-direct seller like Prodiam to quote the loose-stone price for a GIA spec and compare it against a retail quote for the same stone.

Why is the same diamond cheaper from a cutter?

A cutting works sells closer to the trade RAP-minus price and carries far less rent, brand, and stock-financing cost than a mall retailer, so more of the discount reaches you.

When to involve a specialist

If there is a real diamond, the next step is a certificate-led conversation.

Bring the grading report, photos, invoices, valuations, and any estate paperwork. The goal is to move from generic advice to a stone-specific view.

Visit Prodiam

Sources used