The Røros Copper Works () was a copper mining company based in the town (

bergstad Bergstad or Bergstaden is an old classification for a mining town in Norway. In the past, a ''bergstad'' had its own laws, so-called mountain laws. Today, the town of Røros is the only remaining ''bergstad'' in Norway. Before 1683, the mountai ...

) of

Røros Røros may refer to: Places * Røros Municipality, a municipality in Trøndelag county, Norway * Røros (town), a town within Røros Municipality in Trøndelag county, Norway * Røros Church, a church in Røros Municipality in Trøndelag county, No ...

in what is now

Røros Municipality ( Norwegian) or is a municipality in Trøndelag county, Norway. The administrative centre of the municipality is the town of Røros. Some of the villages in Røros include Brekken, Glåmos, Feragen, Galåa, and Hitterdalen. The municip ...

Trøndelag Trøndelag (; or is a county and coextensive with the Trøndelag region (also known as ''Midt-Norge'' or ''Midt-Noreg,'' "Mid-Norway") in the central part of Norway. It was created in 1687, then named Trondhjem County (); in 1804 the county was ...

county,

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

. The mines operated from 1644 until 1977. The Crown designated the area as a

in 1647 and put Joachim Irgens von Westervick in charge, including rights to

forests A forest is an ecosystem characterized by a dense community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological functio ...

and

water resources Water resources are natural resources of water that are potentially useful for humans, for example as a source of drinking water supply or irrigation water. These resources can be either Fresh water, freshwater from natural sources, or water produ ...

within a circular diameter of around the town. The local farmers were given working obligations, such as transport and

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ca ...

production for the copper works. Among the mines were the ''Storwartz'' mines, ''Hestkletten'', ''Christianus Qvintus'', ''Olavsgruven'', ''Kongens Gruve'', and ''Christianus Sextus''. During its operation a total of of

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

and of

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

s was produced.

History

In 1644, the general manager of the mine at

Kongsberg Kongsberg () is a historical mining town and municipality in Buskerud county, Norway. The city is located on the river Numedalslågen at the entrance to the valley of Numedal. Kongsberg has been a centre of silver mining, arms production and fo ...

gave permission to exploit one lode of

in the mountains near Rauhaammaaren. Storvola and Gamle Storwartz became some of the company's most important mines. Nordgruve, another important mining area, was situated to the north east of the town of Røros. In 1685, Røros discovered a considerable amount of associated silver mines. The mining activity lasted for about 40 years, and a total of of

sterling silver Sterling silver is an alloy composed mass fraction (chemistry), by weight of 92.5% silver and 7.5% other metals, usually copper. The sterling silver silver standards, standard has a minimum millesimal fineness of 925. ''Fineness, Fine silver'' ...

was mined. This provided considerable revenue for the Danish-Norwegian treasury to support King Frederick IV in building the palace of

Solbjerg Solbjerg is a south-western suburb of Aarhus in Denmark and one of the outer suburbs of Aarhus. It is located 17 km. from the city centre and has a population of 4,845 (1 January 2025).

. From 1740 onwards, there was a period of greatness for the Røros Copper Works with several mines yielding well. Due to the funding of the Oldenburg royal family, the scale of the Leros silver mine and copper mine expanded. As the mine is close to

Trondheim Trondheim ( , , ; ), historically Kaupangen, Nidaros, and Trondhjem (), is a city and municipality in Trøndelag county, Norway. As of 2022, it had a population of 212,660. Trondheim is the third most populous municipality in Norway, and is ...

and at a lower latitude, the ore output is much higher than Scandinavia

Falun Falun () is a city and the seat of Falun Municipality in Dalarna County, Sweden, with 37,291 inhabitants in 2010. It is also the capital of Dalarna County. Falun forms, together with Borlänge, a metropolitan area with just over 100,000 inhabit ...

. The rich income of the mining area also prompted the royal family to repeatedly ask for an expansion of the mining.

Dynamite Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay), and Stabilizer (chemistry), stabilizers. It was invented by the Swedish people, Swedish chemist and engineer Alfred Nobel in Geesthacht, Northern German ...

was utilised from 1870 and later drilling machines. The electrical generating station built high-tension power lines to supply the mines, starting in 1897. The

Bessemer process The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is steelmaking, removal of impurities and undesired eleme ...

was introduced at the end of the 1800s. The Rørosbanen railway line was completed in 1877. High prices for both

and

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

gave good results, but then the prices dropped and there were several years with large losses. After 333 years, mining activity in

ceased in 1977.

Geology

This region consists of Cambro-Silurian sedimentary rocks (i.e., rocks from the

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

and

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

periods, formed 545 to 417 million years before the present) that are highly

metamorphosed Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...

by the

Caledonian orogeny The Caledonian orogeny was a mountain-building cycle recorded in the northern parts of the British Isles, the Scandinavian Caledonides, Svalbard, eastern Greenland and parts of north-central Europe. The Caledonian orogeny encompasses events tha ...

about 490 to 390 million years ago (Ma). The mountain formation created extensive folding with numerous

anticlines In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

and

syncline In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed ...

s across much of Norway. In addition to Cambrosilurian shales, there are numerous volcanic intrusive sills and dikes. Metal deposits are formed by hydrothermal interaction of fluids between volcanic and surrounding rocks, concentrating copper sulfates in ore zones.

References

{{DEFAULTSORT:Roros Copper Works 1644 establishments in Norway 1977 disestablishments in Norway Defunct copper smelters Copper mining companies of Norway History of Trøndelag Røros