Corundum

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A bluish gray hexagonal crystal of corundum, this the variety called Sapphire, measuring 1.5 cm across embedded up on matrix. In good condition. Collected in 1968.Cancrinite Hill, located in Dungannon Township near Bancroft, Ontario, is a renowned mineral collecting site rather than a commercially operated or formally dated industrial mine, meaning precise commercial opening and closing dates are not applicable. Geologically, the site sits within the Bancroft alkalic belt of the ancient Grenville Province, characterized by silica-poor nepheline syenites, sodalite, and associated metamorphic rocks where rare minerals developed through complex alkaline and metasomatic processes. While the hill is famous primarily for striking yellow cancrinite and blue sodalite, minor occurrences of accessory minerals such as corundum and its varietal phases form locally within these silica-deficient alkaline environments.