Denningite

This specimen features soft yellow platy crystals of denningite, a very rare calcium manganese tellurite, on quartz matrix from the Bambolla Mine in Sonora, Mexico—the type locality for the species.  The Bambollita Mine is approximately 800 metres lower down on the same hill as the Moctezuma Mine. Denningite, first recognized in 1961 and formally named in 1963 after mineralogy professor Reynolds McConnell Denning, is known only from this locality. This piece also shows associations with prismatic yellow-orange tellurite, and possibly spiroffite, although the latter has not been confirmed. The Moctezoma Mine, particularly the Bambolla section, is famous for producing numerous rare tellurium minerals—fifteen type locality species in total. This is a particularly rich specimen from one of the most important tellurium-rich mineral localities in the world.

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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.