Reynold's Cup Competition

2018 Reynolds Cup Now Open

The 9th biennial Reynolds Cup competition for quantitative mineral analysis is now open. You can register your interest in participating in the contest by sending an email to Rieko Adriaens The competition is open to anyone interested in quantitative mineral analysis, with particular emphasis on clay mineralogy. Information about the competition including guidelines and previous winners can be found at The competition is free for all to enter, however, those that are not members of the CMS are encouraged (but not obliged) to become members (see Please use the following format when registering: Subject: Please put "Reynolds Cup 2018 registration" in the subject line in your email request. In the body of the email please put the following information: Name: Institution/organization: Shipping address: (that works for DHL/Courier delivery, e.g. physical address not Postal Box) Phone number (for delivery): Email address: A total of approximately 90 sets of samples will be available for distribution. Each set comprises three samples of approximately 3-4 g with mineral mixtures commonly found in clay bearing rocks. All sets of samples will be distributed in the order of registration. Samples are expected to be shipped at the latest at January 22nd 2018 with the deadline for submission of results by April 16th 2018. The top three contestants with the most accurate results will be announced at the 55th Annual Meeting of the Clay Minerals Society (June 11-14, 2018, Urbana-Champaign, Illinois). Only the names of the top three contestants will be published. The names of the other participants will remain strictly confidential. Because of the popularity of the Reynolds Cup and the enormous amount of work put into its preparation, potential participants are strongly encouraged to plan ahead and only request samples if they are sure they can complete the analysis and return results to the organizers by the due date. Those who request samples and do not send in results or fail to return the samples unopened WELL BEFORE the due date will not be eligible to participate in future Reynolds Cups. A waiting list will be kept to offer returned samples to other potential participants. To ensure an even wider exposure, we encourage you to forward this announcement to your national mailing lists and mineralogy associations, colleagues and friends who might be interested in participating. We look forward to your participation! Rieko Adriaens and Gilles Mertens Reynolds Cup 2018 organizers University of Leuven Celestijnenlaan 200 E 3001 Heverlee (Belgium) email:


The Reynolds Cup competition, named after Bob Reynolds for his pioneering work in quantitative clay mineralogy and his great contributions to clay science, was established in 2000 by Douglas McCarty and Jan Srodon of ChevronTexaco and Dennis Eberl of the United States Geological Survey (USGS). Unlike other round-robin events that used well-ordered, high-symmetry phases (Madsen et al., 2001) or splits from natural samples with unknown mineral composition (Ottner et al., 2000), the Reynolds Cup competition utilizes mixtures of pure standards that represent realistic sedimentary rock compositions. The first RC competition opened early 2002 and samples were made available to individuals in commercial, industrial, government, or academic laboratories, which could use any method or a combination of methods to obtain the most accurate quantitative phase analysis. Three samples each were given to a total of 40 participants. The TOP-3-finishers were presented with plaques and the champion’s trophy went to the first-place finisher. The competition was sponsored by ChevronTexaco and the trophy was donated by the USGS. The success of this competition encouraged the founders to make it a biennial event. The Reynolds Cup competition is now funded by the Clay Minerals Society CMS and the German-Austrian-Swiss Clay Group DTTG. The competition is free for all to enter. However, those that are not members of the CMS are encouraged (but not obliged) to become members.