Plattnerite, Hemimorphite, Calcite

This small cabinet specimen features a striking association of hemimorphite crystals that appear black due to dense coatings of minute, dark brown to black acicular plattnerite—an uncommon lead dioxide mineral—set atop an oxidized limonite matrix. Scattered across the piece are numerous rhombohedral calcite crystals, some of which contain inclusions of plattnerite needles visible under magnification.

The Ojuela Mine, located in Mapimí, Durango, Mexico, is one of the world’s classic mineral localities, credited with producing over 100 distinct mineral species. While many minerals from this prolific mine are relatively common, high-quality plattnerite specimens remain rare and highly sought after. This piece is a fine example of the species and a testament to the mineralogical richness and diversity for which the Ojuela Mine is renowned.

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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.