University of Waterloo
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Waterloo, Ontario, Canada N2L 3G1
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Corundum is a very hard, tough and stable mineral. For all practical purposes, it is the hardest mineral, second only to diamond. It is unaffected by acids and most environments. The name corundum was first derived either from the Sanskrit word Kuirvinda or from the Indian name for corundum, Kauruntoka.
Corundum forms in a variety of geological settings. Generally, these settings are aluminum rich and silica poor. It often appears in light-coloured igneous rocks such as desilicated pegmatites, syenites and Nepheline syenites. Corundum can occur as an accessory mineral in metamorphic rocks, derived from aluminous or carbonate sediments such as crystalline limestone and marbles, mica schist’s and gneisses. Furthermore, it can be found in the contact zone between igneous rocks and limestone’s.
Corundum has the chemical formula Al2O3. Pure corundum is rare in nature, and is completely colourless. Small amounts of metallic elements such as Cr, Fe and Ti can substitute for aluminum in the structure, which gives rise to many colour variations. Some corundum even owes its colour to irradiation, or the elements vanadium, cobalt or nickel. Ruby and sapphire, two varieties of corundum are among the oldest known gems to man, dating back many thousands of years. They have always been held in very tight regard.
In 1876, a girl named Annie and her father Henry Robillard discovered a mass deposit of corundum in a mountainous area. At the time, corundum was used as an abrasive, to cut and polish steel, as a hardener in the making of steel wheels for locomotives and train cars, and finally for grinding optical lenses. This discovery attracted attention and ultimately led to the settlement Craigmont.
In 1900, mining operations began by the Canadian Corundum Company. The first mill was a pilot and produced approximately 20 tonnes of ore per day. In 1904, a larger mill was opened which produced the outstanding amount of 300 tonnes of ore per day. This crushing mill was the heaviest and most powerful ever built in North America.
The town of Craigmount grew to a peak of about 600 persons. It was the world’s largest Corundum producing town at the time. Unfortunately, in 1913, a fire destroyed the mill. This resulted in job loss and gradual decline of residents. Ultimately, by 1921, Craigmont was a ghost town.
The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land promised to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is centralized within our Indigenous Initiatives Office.