The Pontgibaud factory in Couëron diversified into other non-ferrous metal products using imported ore. After being sold and resold it finally closed in 1988.

[3] The different veins of ore at Pranal, Barbecot, Roure, Les Rosiers, La Miouse and Villevieille are mainly oriented in a north-south direction.

[4] The deposits include diverse secondary minerals such as arsenopyrite, anglesite, baryte, bournonite, cerussite, chalcopyrite, freibergite, galena, mimetite, pyrite, pyromorphite, quartz, semseyite, sphalerite, stannite, tetrahedrite and wulfenite.

Many European museum hold samples of these minerals, collected from the Pontgibaud mines by 19th century mineralogists.

[1] Lead extracted in Roman times may have been used to cover the roof of the Temple of Mercury at the summit of Puy de Dôme, a nearby mountain.

[6] At that time mining would have been done by primitive techniques, with hand-powered machinery to hoist up the ore, crush it and sort out the mineral-rich portions.

Although Pallu extracted significant amounts of silver and lead, the business was undercapitalized and the mines began to flood.

Pallu did not have the money needed to build a 18 kilometres (11 mi) adit to drain the mines, a huge project.

[1] The Société des mines et fonderies de Pontgibaud was a limited company authorized by decree in 1847.

[10] The four French directors were Alphonse Pallu, the Count of Pontgibaud and the Paris bankers Ernest Andre and Paul Bontoux.

The four English directors were Charles Morrison, Octavius Ommanney, William Thompson (MP) and John Taylor.

[12] The statutes of the society were registered by Alphonse Pallu, manager, Frédéric-Adolphe Marcuard, banker, and Paul Bontoux, proprietor.

The larger shareholders were Adolphe Marcuard & cie (2,800), Charles Morrison (1,000), William Thompson (1,000), John Taylor et Sons (1,000), Paul Bontoux (529), Octavius Ommaney (500) and D. Forbes-Cambell (500).

[17] The foundry at Pontgibaud processed ore from the nearby Pranal, Barbecot, Roure les Rosiers, La Miouse and Villevieille mines.

[20] Powerful Cornish-type steam pumps removed water from the 250 metres (820 ft) deep Alice and Taylor pits at Brousse and Roure.

[18] The société des mines et fonderies de Pontgibaud lost its title to the Puy-Saint-Gulmier anthracite concession by decree of 18 March 1907 due to prolonged non-exploitation.

[22] The new owners of the company put up several new buildings, inaugurated in 1878, including the lead tower and the big hall (now the media library).

It was the 4th largest producer of non-ferrous metal products in France, occupying a site 950 by 50 metres (3,120 by 160 ft) along the bank of the river below a cliff.

[28] Mounds of infertile yellow spill dotted the landscape around Pontgibaud for many years after mining ended.

[18] A century after the mines were closed there remained nearly 60 traces of open and dangerous shafts and galleries, which were made safe in 2009.

The deposits contain no organic material, have steep slopes and have high metallic content, all of which prevent growth of vegetation.

They are subject to strong erosion by water and wind, which impacts the Sioule river and the neighboring lands in a region that is now very dependent on tourism.

[31] Between 1886 and 1891 César de Pontgibaud had the old donjon, which had been abandoned since the time of Louis XIII, restored by a disciple of Eugène Viollet-le-Duc.