Zemannite

This specimen features minute brown crystals of zemannite in several spots on the specimen. Zemannite is a rare and chemically complex magnesium zinc iron tellurite hydrate, first discovered in 1961 in gold-tellurium ores from the Bambolla Mine, part of the Moctezuma mining district in Sonora, Mexico. With the formula Mg₀.₅ZnFe³⁺[TeO₃]₃·4.5H₂O, zemannite is a secondary oxide mineral that forms small prismatic crystals within the hexagonal crystal system. It typically occurs in the oxidized zones of hydrothermal Au-Te deposits, often in association with other rare tellurium oxysalts.

Due to its extreme rarity and minute crystal size, zemannite has no industrial applications and is valued solely as a collector’s mineral. It was named in honour of Dr. Josef Zemann, a renowned crystallographer and expert on tellurium minerals, who served as Professor of Mineralogy at the University of Vienna. According to Mindat.org, zemannite is confirmed from only four localities worldwide, with the Moctezuma Mine serving as its type locality.

--

This specimen comes from the collection of Dr. Peter Tarassoff, a prominent figure in mineralogy, particularly known for his work at Mont Saint-Hilaire (MSH). His diligent collecting and examination efforts have led him to be the first to identify at least 35 species and discover 12 new species, not only at MSH but also at other alkaline localities. Dubbed the "Dean" of Mont Saint-Hilaire collectors, Peter was honoured with the naming of the new species petarasite in 1980. He has authored or co-authored numerous mineralogical articles and has been a member of the Mineralogical Association of Canada since 1964. Additionally, Peter has volunteered at the Redpath Museum for the past 21 years, where he was formally appointed the Honorary Curator of Mineralogy. In recognition of his significant contributions to mineralogy, Peter was awarded the 2017 Pinch Medal.