As I mentioned in my first posting on this blog, the year we moved into New Edinburgh (1966), located on the NE corner of Crichton and Dufferin, was the former Blackburn Bros. mica factory.
I am not sure when it closed. I doubt it was still in operation at that point and shortly afterwards, the building was demolished.

The lot remained vacant for a good many years until a condominium building was built there. For a good many years, however, you would find chunks of mica lying about, between lumps of dog poo and broken bottles.

While New Edinburgh is now a quiet residential neighbourhood, it was once a thriving industrial and business area, as well as the home of those working in the area. Rocklciffe Village, to the north, which is now the home of mansions and embassies was once the home of those who were in service to the rich who lived in Sandy Hill and other areas of the city, as well as government and clerical workers.

Along the Rideau River which flows just two blocks away, from Crichton Street were heavy industry, chemical manufacturers, sawmills and other water-powered mills (located both at the Rideau Falls, where the Rideau plunges into the Ottawa River, but further upstream where Cummings Bridge crosses the Rideau at Montreal Road), rail-yards for both train and streetcars, foundries, amongst others.

202 Crichton Street (or Creighton, according to the directory listing, below)

200 Crichton Street

The Blackburn Brothers apparently also a mica mine in Hull Township. I am wondering if this is the one, now abandoned, located near Chelsea, Quebec. My mother used to take us up there on field trips, as well as her high school geography students and several generations of kids from our Sunday school.

Mica was a very important mineral and was used in a wide variety of processes including as an insulator in high voltage electrical eq uipment, manufacturing capacitors for radio frequency applications, used instead of glass in windows for stoves and kerosene heaters (and in greenhouses), pressed into a thin film and used on Geiger-Müller tubes to detect low penetrating Alpha particles, in cosmetics, used in the creation of “interference paints”, used in heating elements, as a substrate for sample preparation for the atomic force microscope, and as clean imaging substrates in atomic force microscopy….

It has been used since prehistoric times (as a pigment for cave paintings) and in windows before the it was discovered how to create glass in sheets. At the Pyramid of the Sun at Teotihuacan, near Mexico City, contained considerable amounts of locally mined mica in layers up to 12 inches thick. It continues to be used by the Hindus during Holi, in the pigments thrown during the festivities.