Arfvedsonite

This specimen features an attractive assemblage of numerous thin, prismatic arfvedsonite crystals—a somewhat uncommon find. The highly lustrous, striated, jet-black blades contrast nicely against the bit of brown matrix and display excellent form with some bruising but no major damage. Arfvedsonite, a sodium-rich member of the amphibole group, is known for its distinctive clinoamphibole cross-sections, which are clearly visible when viewed down the "c" axis. The sculptural arrangement of the crystals adds a strong three-dimensional presence, making this a striking and well-balanced example of the species.

Mont Saint-Hilaire is considered one of the most mineralogically diverse localities in the world, having produced hundreds of rare and unique mineral species—including many of the finest best-of-species specimens ever found. The entry on mindat.org states that there are 440 different species found there, and this quarry is the type locality for 73 of them. Once accessible to collectors, the quarry is now under strict control, with field collecting entirely prohibited. As a result, specimens like this one have become increasingly scarce and sought after by collectors.

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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.