Latitude: 45°30'15"N
Longitude: 73°34'38"W
The type occurrence of Dawsonite was a trachytic (feldspathic) dike cutting Trenton limestone "near the western end of McGill College [now McGill University]" adjacent to The Arts Building.
The type Dawsonite specimens were collected between 1855 and 1874 first by Dr. A. F. Holmes and then Principal William Dawson. Although Dawson recognized the material as a likely new species, B. J. Harrington published the first description of the new mineral in 1875.
Dawsonite occurred in veinlets in joints, formed on cooling of the dike, and in clusters. Associated minerals include Calcite, bundles of Kaolinite crystals, cubes of Pyrite and Fluorite.
What may have been the same dike was encountered in September and October of 1963 during construction of The Leacock Building and again in 2002 and 2003 during construction of The Penfield 740 Building and The Trottier Building.
Mineral List
9 entries listed. 8 valid minerals. 1 type locality (valid mineral).
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References
HARRINGTON, B.J. (1874) Notes on Dawsonite, a new carbonate. The Canadian Naturalist and Quarterly Journal of Science, VII, 305 309.
HARRINGTON, B.J. (1878) Note on the composition of dawsonite. The Canadian Naturalist, New series, X, 84 86.
- Stevenson, John S., The Petrology of Dawsonite at the Type Locality, Montreal, The Canadian Mineralogist, 1964
- Donald Doell personal observations