The Coxheath copper mine is an example of the many historical Nova Scotian mines that extracted what are now called “critical minerals” – minerals needed for things like electric vehicles, wind turbines, solar panels and electronics.

Those early mines proved that we have the geology for critical minerals and that Nova Scotia can contribute to global supply of these essential materials today.

Copper was first found at Coxheath, Cape Breton, in 1875. A Geological Survey of Canada report that year said “a considerable quantity of yellow and purple copper pyrites” was documented at the source of Grantmire Brook (now known as Copper Brook).

In 1881-82, four shafts were sunk by the Coxheath Copper Mining Company, which was backed by Boston interests.

In 1886, E. D. Peters, a well-known metallurgist, studied Coxheath and the local availability of materials necessary for smelting (i.e. coal, limestone and iron) and concluded that copper could be smelted at Sydney Harbour cheaper than anywhere in the United States. Fuel, fluxes, shipping facilities and labour were all easily available, and the mine’s prospects seemed bright.

In 1887, the Coxheath Mining Company was reorganized into the Eastern Development company and work continued.

In 1889, the French Copper Syndicate, which controlled the global copper price, failed and no work was done at Coxheath. Work started again in 1890-91 and a new copper vein, the Mountain Vein, was discovered.

The New York Engineering and Mining Journal visited Coxheath in 1891, an indication of the mine’s importance. However, work continued on only an irregular basis for the next decade until the mine shut down in 1901. It is not clear why the Eastern Development Company closed the mine, but the company turned its attention to lumber.

In 1893, the Eastern Development Company sent one ton of Coxheath ore, grading 10% copper, to Chicago’s world fair and displayed it as part of Nova Scotia’s exhibit. Coxheath ore was also displayed at fairs in Paris and Glasgow over the years.

The mine was idle until 1928 when Arno Mines Limited struck an option agreement with the Armada Syndicate. Unfortunately, legal action ensued because Noah Timmins and Arthur P. Earle, President of the Montreal Insurance Company, claimed they had a prior agreement with Armada. The court case received considerable media coverage and Arno Mines won in the end.

Arno did exploration work in 1928 and installed a mining plant and 18 buildings in 1928-29. However, the company ran out of capital in September 1930 as a result of the Great Depression and operations ceased.

Nova Scotia’s Department of Mines did exploration work at Coxheath in 1947 and partially dewatered the No. 2 Shaft.

From the early 1950s to today, Coxheath has been explored by a series of companies.

Today, the mine’s value has never been more obvious as the world rushes to find and develop critical mineral deposits needed for green technologies like electric vehicles and renewable energy.

Copper is essential to green technologies because it is used in most electrical wiring. The more renewable energy we generate and the more electric vehicles we build, the more copper we will need.

Other important metals have also been found at Coxheath, including gold, cobalt, silver and molybdenum. Other metals in the deposit could strengthen the business case for the mine and allow it to contribute to global supply of other metals used in green technologies.