The Sheahan Diamond Literature Reference Compilation is compiled by Patricia Sheahan who publishes on a monthly basis a list of new scientific articles related to diamonds as well as media coverage and corporate announcements called the Sheahan Diamond Literature Service that is distributed as a free pdf to a list of followers. Pat has kindly agreed to allow her work to be made available as an online digital resource at Kaiser Research Online so that a broader community interested in diamonds and related geology can benefit. The SDLRC Blog is a guest commentary by an industry expert about articles, themes and trends in recent issues of the SDLRC.
Comments by Brooke Clements
Brooke Clements is President and CEO of Craton Minerals Ltd., a Vancouver-based private diamond exploration company focused on discovering North America's next diamond district. He is also President of JBC Ventures Ltd., a consulting company specializing in mineral exploration and community and government relations. From 2007 to 2015 he was President of Peregrine Diamonds Ltd. where he led the team that discovered the Chidliak diamond district on Baffin Island in the Canadian Arctic. Before that, Brooke was Vice President, Exploration for Ashton Mining of Canada Inc. Under his leadership, Ashton and their partner SOQUEM discovered the Renard diamond district in Quebec where the Renard Diamond Mine commenced production in 2016. From 1982 to 1997, Brooke was an Exploration Geologist and Regional Manager for Exmin Corporation where he conducted diamond exploration programs throughout the United States. He holds a BSc in Geology from Indiana University and an MSc in Economic Geology from the University of Arizona.
Brooke Clements has volunteered to highlight the articles that caught his attention in the monthly reference compilations. The opinions expressed are solely his and he can be reached at .
ALROSA produces about 90% of Russia's diamonds representing about 30% of world rough production, about 30 million carats a year. They also have the world's largest diamond reserves, about 1 billion carats. This article in Jeweller Magazine does a good job of summarizing the current situation regarding Russian diamonds in light of the Ukraine war (click here for an excellent graphic in the article about global diamond production and producers). Though some sanctions have been applied to ALROSA and Russian diamonds, on March 23, sales of Russian rough were still taking place. The United States now prohibits the import of "non-industrial" Russian diamonds. However, the purchase of Russian diamonds that have undergone "substantial transformation" (polished and jewelry) is not prohibited. Most polished diamonds are untraceable back to their origin. About 95 per cent of the world's diamonds are polished in India and cannot be easily identified as being produced from Russian rough. It has been suggested that the global trade of Russian rough should be blocked immediately. One mechanism would be for the Kimberley Process to ban the export on Russian diamonds, but that would require the agreement of member nations. This could lead to higher prices for those producing the remaining 70% of the world's rough. It would still take some time for "Russian" polished to work its way through the system. It all means uncertainty for diamond and jewelry markets for at least the near-term. In the end, the diamond and Jewelry industries and ultimately the consumer will determine where it all goes. Consumers may want guarantees that they are not buying a Russian diamond so there will be an increasing demand to supply source information for polished stones. Diamonds for which that information is not available might start selling at a discount or be avoided altogether by the consumer. Some fear that consumer uncertainty regarding the source of natural diamonds could lead to increasing appetite for man-made stones. It's worth noting that Tiffany and Signet have "self-sanctioned", pledging not to buy any diamond with a Russian origin.
A good summary outlining the problems the industry faces as it decides how to deal with Russian rough with emphasis on the challenges to India. The challenges in providing source information for polished stones are outlined.
Carbon isotopes of kimberlite magmas were studied and the authors concluded that there was a fundamental change in deep mantle carbon source compositions during the Phanerozoic. The 13C/12C of kimberlites before 250 Ma have typical mantle values and younger kimberlites have lower and more variable ratios
An interesting study of a Jurassic-aged placer diamond deposit located within the Yakutian kimberlite province in Siberia. The authors describe the placer deposit and compare its diamonds with those from kimberlites in the nearby Nakyn kimberlite field where the Nyurbinskaya pipe is being developed. They conclude that diamonds in the placer were eroded from at least two pipes in the Nakyn field, with no exotic diamonds present and that it took about 300 metres of erosion to produce the placer deposit.
A good summary of indicator mineral exploration techniques with Canadian case studies. A review of Automated Mineralogy techniques like QEMSCAN is included. A table with ten deposit types and references to indicator mineral studies for each type is included along with a comprehensive list of references.