Tellef Dahll (10 April 1825, in

Kragerø Kragerø () is a municipality in Telemark county, Norway. It is located in the traditional districts of Grenland and the smaller Vestmar. The administrative centre of the municipality is the town of Kragerø. Villages in Kragerø include H ...

– 17 June 1893, in

Morgedal Morgedal is a village in Kviteseid Municipality in Telemark county, Norway. The village is located in the mountains along the European route E134 highway, about to the northwest of the village of Brunkeberg (Telemark), Brunkeberg and about to t ...

) was a Norwegian

mineralogist Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

and

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

Life

After graduating in minearology from the

University of Christiania The University of Oslo (; ) is a public research university located in Oslo, Norway. It is the oldest university in Norway. Originally named the Royal Frederick University, the university was established in 1811 as the de facto Norwegian conti ...

in 1846, Dahll worked for private mining companies. He found

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

on the island of

Andøya , , or is the northernmost island in the Vesterålen archipelago, situated about inside the Arctic Circle. Andøya is located in Andøy Municipality in Nordland county, Norway. The main population centres on the island include the villages of ...

iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the f ...

Bjørnevatn , , , or is a village in Sør-Varanger Municipality in Finnmark county, Norway. The village lies about south of the town of Kirkenes and about west of the Norway-Russia border. The village has a couple of suburbs including Hesseng to the nort ...

and in 1867 Dahll discovered

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

from the Tana and

Anarjohka Anarjohka (, or ''Anarjohka'', , ) is a tributary of Tana River (Norway), Tana River. It is about long, with a drainage area of about .NVE Atla ...

rivers, which launched the 1870 gold rush in the Finnish Lapland. Since 1858 Dahll and

Theodor Kjerulf Theodor Kjerulf (30 March 182525 October 1888) was a Norway, Norwegian geologist and professor at the University of Oslo. He also served as director of the Norwegian Geological Survey. Biography He was born in Oslo, Christiania (now Oslo), Norway ...

led the first

geological survey of Norway Geological Survey of Norway (), abbreviation: ''NGU'', is a Norwegian government agency responsible for geologic mapping and research. The agency is located in Trondheim with an office in Tromsø, with about 200 employees. It is subordinate to ...

.Fontani, Marco & Costa, Mariagrazia & Oma, Mary Virginia: ″The Lost Elements: The Periodic Table's Shadow Side″, p. 136. Oxford University Press, 2014.
Google Books
/ref> In 1879 Dahll collected samples of

nickel arsenide Nickel arsenide is a compound of nickel and arsenic and component of the ore nickeline. It is highly toxic and a known carcinogen in humans. Uncontrolled decomposition of nickel arsenide can give rise to further toxic nickel compounds. Toxicit ...

and

gersdorffite Gersdorffite or ''Nickel glance'' (trivial name) is a nickel arsenic sulfide mineral with formula NiAsS. It crystallizes in the isometric system showing diploidal symmetry. It occurs as euhedral to massive opaque, metallic grey-black to silver w ...

on the island of Oterøya in his birthplace Kragerø. Dahll found out that the rocks contained previously unknown element which he named Norwegium. The phosphate mineral dahllite (hydroxylapatite) is named after Tellef Dahll and his brother, the mineralogist Johann Dahll.Dahllite Medical Definition
Merriam-Webster Medical Dictionary. Retrieved 1 October 2015.

References

1825 births 1893 deaths People from Kragerø University of Oslo alumni 19th-century Norwegian geologists Norwegian mineralogists Members of the Storting 1865–1867 {{Norway-scientist-stub