Polished Prices
Polished Prices
The London-based independent benchmark service for polished-diamond pricing
Polished Prices is an independent polished-diamond price index and benchmarking service based in London, providing wholesale pricing data across size, colour, and clarity categories as an alternative reference to the better-known Rapaport Diamond Report and IDEX Online indices. Polished Prices aggregates transaction data from dealers and manufacturers and publishes price tables that are used by traders, banks, and investors for pricing guidance and inventory valuation.
Position in the benchmark landscape
The polished-diamond pricing benchmark market is dominated by Rapaport, with IDEX Online holding a meaningful secondary position and Polished Prices serving as a third independent reference. Rapaport's incumbency means that the standard format for trade quotes in much of the industry is a discount to the Rap List; Polished Prices and IDEX provide alternatives that are referenced when the parties have not committed to Rapaport as the contract benchmark, or when one of the parties wants an independent cross-check.
The independent provenance of Polished Prices, separate from any particular trade or trading platform, is the principal feature that distinguishes it for some users. Banks providing diamond-stock financing and investors evaluating diamond investment vehicles sometimes prefer the Polished Prices reference for the same reasons that financial markets generally value third-party-validated benchmarks: the absence of a direct stake in the trade flows being measured.
Methodology
Polished Prices aggregates transaction data through dealer surveys, transaction submissions, and published trade data, then weights the data and publishes price tables across the standard size, colour, and clarity matrix used in the diamond trade. The published tables describe wholesale price levels for round-brilliant diamonds in the principal commercial size and quality combinations, with separate references for fancy shapes.
As with all polished-diamond indices, Polished Prices faces the limitation that the underlying market is fragmented and partially opaque. The index aggregation is necessarily incomplete; particular thin-market combinations may show prices that diverge meaningfully from actual transaction levels. Experienced users of the index understand these limitations and apply them appropriately as part of their negotiation and valuation work.
Use in the trade
Polished Prices is used principally as a reference rather than as a transaction benchmark. Traders cross-check Rapaport quotes against Polished Prices when negotiating; banks use the data as one input to collateral valuation; investors use the data to evaluate the performance of diamond investment vehicles. The trade's working benchmarks for actual quotation purposes remain principally Rapaport, with IDEX as a secondary reference, but Polished Prices fills the role of independent third-party validation that serves the financial side of the industry.