Carmeltazite, Mineral of the year 2018
We are pleased to announce that for 2018 the “Mineral of the Year” award has been assigned to Carmeltazite.
The new complex oxide carmeltazite (ZrAl2Ti4O11) forms black inclusions in blue corundum crystals (“Carmel SapphireTM”) from Cretaceous pyroclastic rocks and associated alluvial deposits at Kishon Mid-Reach in northern Israel. Its name alludes to the type locality at Mt. Carmel and the three principal metals in its formula (Ti, Al and Zr). Carmeltazite was discovered by William L. Griffin (Macquarie University, Australia), Sarah E.M. Gain (University of Western Australia), Luca Bindi (Università degli Studi di Firenze, Italy), Vered Toledo (Shefa Gems Ltd., Israel), Fernando Cámara (Università degli Studi di Milano, Italy), Martin Saunders (University of Western Australia), and Suzanne Y. O’Reilly (Macquarie University). Since its description was published in Minerals (Griffin et al., 2018), the mineral has gained much publicity online as “the world’s newest gemstone” (EraGem, 2019), and even an “extraterrestrial mineral harder than diamonds” (Flatley, 2019). Although perfectly terrestrial in origin and not particularly gemmy, the Mineral of the Year 2018 does contain Ti3+, altogether rare in the geological environment, and possesses a peculiar crystal structure, which is remotely related to the close-packed arrangement of spinel. As can be seen from its formula, the structure of carmeltazite is cation- and anion-deficient relative to spinels, while its symmetry is reduced to orthorhombic. Perhaps even more remarkable than its public image or structure is the association of carmeltazite with other Ti3+ and carbide minerals, which indicates very unusual geological conditions in their volcanic cradle and promises new exciting discoveries in the future (Griffin et al., 2018).
We would also like to acknowledge here the close runners-up, which included the modular carbonato-phosphato-silicate aravaite from pyrometamorphic rocks of the Hatrurim Complex in Israel (Krüger et al., 2018) and the first-ever tin sulfate genplesite from the Oktyabr’skoe Cu-Ni-Pd-Pt deposit in Siberia, Russia (Pekov et al., 2018). Once again, we congratulate Bill Griffin and his co-authors on their interesting discovery.
Check out its structure, and its amazing color.