ROWLEYITE, Mineral of the year 2017

We are pleased to announce that for 2017 the “Mineral of the Year” award has been assigned to rowleyite.

The prestigious title went to black cuboctahedral crystals peppering green mottramite in an underground tunnel at the abandoned Rowley mine in Arizona, and named for the type locality rowleyite. The chemical formula of this new species is as complex as its crystal structure, and both are a testament to the capabilities of modern science and to the uniqueness of geological conditions that led to rowleyite crystallization. Although structurally related compounds are known in materials science as “salt-templated mesoporous solids” and “polyoxometalates”, it is difficult to succinctly identify something that has the formula [Na(NH4,K)9Cl4][V25+,4+(P,As)O8]6·n[H2O, Na,NH4,K,Cl]. Rowleyite can be described as a phosphovanadate with a zeolite-like, porous framework, in which small cages host the [(NH4,K)9Cl4]5+ clusters forming a “salt net” and large cages accommodate H2O, NH4, Na, K and Cl. This paragon of mineralogical complexity was discovered and published in American Mineralogist (volume 102, pages 1037-1044) by Anthony R. Kampf (Natural History Museum of Los Angeles County, USA), Mark A. Cooper (University of Manitoba, Canada), Barbara P. Nash and Thure E. Cerling (University of Utah, USA), Joe Marty (Salt Lake City, Utah), Daniel R. Hummer (Southern Illinois University, USA), Aaron J. Celestian (Natural History Museum of Los Angeles County), Timothy P. Rose (Lawrence Livermore National Laboratory, USA), and Thomas J. Trebisky (University of Arizona, USA). Congratulations to the winning team on this exciting discovery!

The two closest runners-up were kegginite (another polyoxovanadate from the Packrat mine in Colorado, described by Anthony R. Kampf and colleagues (2017) in American Mineralogist and the Ti3+-dominant garnet rubinite discovered in the Vigarano, Allende and Efremovka carbonaceous chondrites by Chi Ma et al. (2017).

How does it looks like, check it out, here.


Kampf AR, Cooper MA, Nash BP, Cerling TE, Marty J, Hummer DR, Celestian AJ, Rose TP, Trebisky TJ (2017) Rowleyite, [Na(NH4,K)9Cl4][V5+,4+2(P,As)O8]6·n[H2O,Na,NH4,K, Cl][Na(NH4,K)9Cl4][V25+,4+(P,As)O8]·n[H2O,Na,NH4,K,Cl]⁠, a new mineral with a microporous framework structure. American Mineralogist 102: 1037-1044

Kampf AR, Hughes JM, Nash BP, Marty J (2017) Kegginite, Pb3Ca3[AsV12O40(VO)]·20H2O, a new mineral with a novel ε-isomer of the Keggin anion. American Mineralogist 102: 461-465
Ma C, Yoshizaki T, Krot AN, Beckett JR, Nakamura T, Nagashima K, Muto J, Ivanova MA (2017) Discovery of rubinite, Ca3Ti3+2Si3O12, a new garnet mineral in refractory inclusions from carbonaceous chondrites. 80th Annual Meeting of the Meteoritical Society 2017 (LPI Contrib. No. 1987), 6023.pdf