Many manganese deposits have been discovered in Hants County, along the south shore of Minas Basin. Most of them, about 25, are located between Cheverie and Minasville.

About 8000 tons of manganese ore were produced along the south shore of Minas Basin and over half of it came from the Tennycape Mine, Nova Scotia’s largest manganese mine and, for a time, one of the biggest producers in Canada.

Manganese was discovered at Tennycape in 1861 by Nicholas Mosher of Avondale, in manganese-bearing boulders in the soil above the actual manganese deposit. He sent a 24 pound sample of ore to London’s International Exhibition in 1862 to be displayed. In that year, the Mosher Company began mining manganese from open cuts in limestone and from the overlying soil.

The first shipment, consisting of 33 barrels holding about seven tons of ore, was shipped from Windsor, Hants County, to England in 1863. Analysis in England found that the ore was remarkably pure. Half of the shipment sold for £8.10 (English currency) per ton and the other half for £9 per ton to different purchasers.

In the mid-1860s, mining was done by several operators including Messrs. Mosher, Nash and Company, Messers. Weeks, Ouseley and Company, and Messers Duvar and Company.

J. D. Nash received an Honourable Mention for his exhibit of a large 150 kilogram mass of manganese ore at the Dublin International Exhibition in 1865.

Henry How, a professor at Windsor’s King’s College, wrote in his 1868 book about Nova Scotia’s mineralogy that a cargo of 120 tons of Tennycape ore was sunk on its way to England – twice! – but somehow eventually made it there and was sold in Liverpool, England, at £8, 5 shillings per ton.

Between 1870-1875, several open cuts in the limestone yielded a high-grade manganese ore. One large lens produced 1,000 tons of ore over ten years. (In geology, a lens is a body of ore/rock that is thick in the middle and thin at the edges, resembling a convex lens.)

From 1879-1892, annual production was about 130 tons and the site was mined by J. W. Stephens. He was followed by Messrs. McVicar and Shaw in 1895.

About 4,000 tons of manganese oxides were produced at Tennycape between 1880-1900. The mine had five or six shafts and several tunnels. Ore was extracted by hand and sorted to some extent into two grades. Ore was crushed at the mine, concentrated and put into barrels for shipment.

In 1917-18, an American company dewatered and sampled the mine, but nothing further was done and the property has been idle ever since.

In 1939, the waste rock pile at the main workings was sampled for the Nova Scotia Department of Mines. It was calculated that the dump contained 35,000 tons of rock and that 660 tons of manganese were in that material.

The Tennycape Mine had a reputation for producing world class examples of pyrolusite, the main manganese-ore found there. Examples of it have been included in many mineral books and mineral specimen collections around the world. In addition to the exhibitions mentioned above, Tennycape’s ore was also displayed at the Philadelphia International Exhibition in 1876, at the Colonial and Indian Exhibition held in London in 1886 and at the Paris International Exhibition in 1900.

Tennycape’s ore was very pure and produced flint glass, which is used to make lenses and prisms, free of the greenish tinge caused by iron. The ore was also used to produce glass pastes, black enamel for pottery, tiles and printing on calico fabric.

Today, manganese is a critical mineral in green technologies. For example, it is a key component in the cathode material used in high-performance lithium-ion batteries.