Lake Ainslie

Barite was first identified in the Lake Ainslie area of Cape Breton in 1890, but local residents had recognized a peculiar white rock on their farms several years prior. Blocks of it, some as long as eight feet and too heavy to move, were found at the foot of some hills on the east side of the lake. Smaller pieces of it were tossed to aside by farmers to get them out of the way of their plows.

Barite is surprisingly heavy – its name comes from the Greek word "barys" which means "heavy” – so it attracted the attention of youth around Lake Ainslie. They had contests to see who could throw pieces of it the farthest.

Eventually it came to be understood that the heavy, white boulders strewn about the fields were not quartz but barite, which was valuable.

Operations began in the early 1890s at the lower Johnson mine which was run by Henderson and Potts, paint manufacturers in Halifax who operated several barite mines because barite is a pigment in white paint.

Two tunnels were eventually dug, an upper and a lower, into the hill about 200 feet where a vertical vein of barite was found.

The ore was carted around the southern end of Lake Ainslie, which is the largest freshwater lake in Nova Scotia, to Whycocomagh for shipment via Ainslie Glen. The carting cost two dollars per ton.

Henderson and Potts extracted 3,574 tons by 1904. No mining was done that year because there was still stockpiled material at the mine.

From 1902 to 1906, H. H. Harrison mined on Bald Hill on the farm of D. J. MacDougall. Harrison was the manager of Henderson and Potts’ mine but had formed a separate prospecting company to look for other barite deposits in the area. In 1903-04, he found veins on the adjacent farms of A. A. MacMillan and T. E Campbell. The H. H. Harrison Prospecting Syndicate changed its name to the Gairlock Mining Company as it transitioned from looking for barite to mining it.

In 1906, the Ainslie Mining and Milling Company succeeded the Gairlock Mining Company and continued operations on Bald Hill. Some of the ore it extracted was crushed in a converted gristmill near the house of D. J. MacDougall and some of it in a similar mill near the head of Lake Ainslie.

Also in 1906, barite was discovered on the north bank of the Trout River near its mouth. This vein later came to be known as the Evans.

All of these operations had shut down by 1911 but a new project was started that year on what records refer to as Peter Campbell Hill near Scotsville. Nova Scotia’s first barite grinding mill was built and preparations for mining began. H. H. Harrison’s new company, Barytes Ltd., was the operator.

Mining took place on Peter Campbell Hill from 1912-17. Five tunnels were dug on the western side of the hill.

In 1920, a few hundred tons were extracted from the old Johnson mine but the Lake Ainslie mines were then idle for a decade and a half.

In 1935, H. M. Evans formed the North American Mining and Chemical Corporation and got the mining rights from the Johnson mine to Scotsville. However, Evans did no actual mining.

In 1939, he got R. T. Gillman interested in the area. Gillman was the first to recognize the area’s potential for the mineral fluorspar. Fluorspar has many uses, one of them being as a flux that removes impurities in the production of steel, iron and other metals. About 20-60 pounds of fluorspar is used to produce one ton of metal.

Gillman held the lease on the vein near the mouth of Trout River for a year but then let it lapse. The property was optioned to the Dominion Steel and Coal Company which drilled seven exploration holes in search of fluorspar, but later abandoned the property.

In 1942-43, under an agreement with Evans, William Papke worked at the Trout River site. The extraction was small-scale, done by hand. (Papke was also involved with gold mining, having done prospecting in the Cochrane Hill gold district and mining in the Brookfield gold district).

The Department of Mines did exploration work at Lake Ainslie during WWII, including drilling three exploration holes. This was part of a province-wide exploration program to find minerals needed for the war effort. Fluorspar was needed for manufacturing steel and barite was needed because it is a key ingredient in drilling mud - a heavy, viscous fluid mixture that is used in oil and gas drilling operations to carry rock cuttings to the surface and also to lubricate and cool the drill bit. The drilling mud, by hydrostatic pressure, also helps prevent the collapse of unstable strata into the borehole and the intrusion of water from water-bearing strata that may be encountered. Barite makes drilling safer and more efficient.

(The former Walton barite mine in Hants County provided barite for the oil and gas industry. That mine is a beautiful lake and greenspace today.)

Today when we talk about “critical minerals,” we mean minerals like lithium and copper that are essential for things like electronics and green technologies. However, society’s mineral needs are constantly changing, particularly as new technologies and new uses for minerals are invented, so what we consider critical also changes constantly. Minerals like barite and fluorspar were critical during the war and remain very important today.

In 1944, Canadian Industrial Minerals Ltd. did some exploration work at Lake Anslie as well as at the barite deposit in Brookfield, Colchester County. Canadian Industrial Minerals later operated the Walton barite mine in Hants County, one of the largest barite deposits in the world.

There were years when Lake Ainslie’s barite mining was the only barite production in Canada. Production statistics from 1904-20 show that Nova Scotia mines provided almost all the Canadian production of barite in that period.

In 1984, mining briefly returned to Lake Ainslie when Scotsville Mineral Resources did a bulk sample at the MacInnis Mine.

In 1879, Baron Franz von Ellershausen had a plan to drain Lake Ainslie to prepare for drilling for oil beneath the lake. The plan ended in scandal but Ellershausen had an extraordinary career in mining and pulp and paper. See his story at