Above image: Octahedron-shaped rough diamonds that are approximately 3-carats each at a manufacturer in Antwerp. (Source: Paul Zimnisky)


Given the highly concentrated state of the global diamond mining industry, the relatively opaque nature of rough diamond trading and the lack of fungibility of diamonds, reliable, easily-assessable rough diamond price information has traditionally been difficult to source. Thus, the Zimnisky Global Rough Diamond Price Index was created to consolidate reliable natural rough diamond price information and publish the current price change of natural rough diamonds on a weekly basis in the form of an index. More specifically, the aim of the Index is to track the like-for-like price change of natural rough diamonds priced in U.S. dollars weighted according to the global product mix. 

The proprietary index methodology incorporates price data from rough diamond transactions in the "primary-market," e.g. sales via long-term contract, as well as, the "secondary-market," e.g. tender, auction and trading, by commercial miners. The Index also includes a minor sensitivity to polished diamond prices given the symbiotic nature of rough and polished —some miners utilize the current polished market as a model factor when setting contract pricing of rough. In addition, the Index includes a minor sensitivity to stand-alone diamond mining equities, as the relative liquidity that equities provide can imply the current profitability and revenue generation ability of diamond miners, which is directly influenced by the current rough diamond market.

Please note, the value of the Index is not meant to reflect the average price per carat of a diamond, instead the current Index value represents the percentage change in the price of rough diamonds from the initial Index value set at 100 on December 31, 2007. The Index is subject to revision, typically as far back as the most recently completed calendar quarter. The Index exclusively tracks natural diamond prices and thus does not include man-made diamond price data.

**For more detailed diamond price data and in-depth industry analysis, please consider subscribing to PZDA's State of the Diamond Market, a leading monthly diamond industry report.

Historical Data for Purchase:

Long-term consolidated Zimnisky Global Rough Diamond Price Index data is available for purchase. Sub-Index data sets are also available for purchase, e.g. by carat-size, quality, primary/secondary market etc., as well as, polished diamond price data and lab-grown diamond price data. Please inquire for availability and pricing.


Reporters and journalists can use and reference the Index without direct permission as long as: 1) the content will be publicly disseminated, 2) the Index is referenced as “the Zimnisky Global Rough Diamond Price Index,” 3) a link back to this page is provided where possible. For private usage of the Index please inquire for more information. 

Disclaimer: Discretion is used in the calculation of the Zimnisky Global Rough Diamond Price Index and thus the accuracy of the Index as a measure of rough diamond prices cannot be guaranteed. This information is strictly to be used for informational purposes and is not investment advice. Paul Zimnisky holds zero accountability for any and all financial losses or otherwise from use of this Index.