It is surprising to think that beneath the city of Montreal, where the Geological Survey of Canada was first established in 1842 and headquartered until 1881, there would be any mineralogical treasures not yet known. But there were. In 1966, at the Francon limestone quarry, about 8 kilometres from Mount Royal, a rare unknown mineral was unearthed inside cavities found in the 2 m thick St-Michel sill that intrudes the limestone.
Survey mineralogist Ann Sabina discovered the new mineral during her very first visit to the quarry – and it proved to be the first known strontium zirconium carbonate. Sabina named it weloganite in honour of Sir William Edmond Logan, the Survey’s founder. It has distinctive large crystals ranging from pale white to lemon yellow in colour.
The new mineral also turned out to be abundant. Weloganite has been found at the Lafarge quarry in eastern Montreal and at the Poudrette quarry in Mont St-Hilaire. Interestingly, the Francon quarry is the type locality for ten new mineral specimens, making it the second most prolific type locality in Canada. Weloganite is featured in major museums and private collections worldwide.
Category: Rocks, Fossils, Minerals and Meteorites
Sabina, A.P., Jambor, J.L., and Plant, A.G., 1968. Weloganite, a new strontium zirconium carbonate from Montreal Island, Canada; Canadian Mineralogist, v. 9, no. 4, p. 468–477.
Tarassoff, P., Horváth, L., and Pfenninger-Horváth, E., 2006. The Francon Quarry, Montréal, Québec; The Mineralogical Record, v. 37, p. 5–60.
Most prolific type localities, Mindat.org. http://www.mindat.org/toptypelocs.php