Mineral description : Euxenite

Euxenite from Godkärra.
Two small samples. Euxenite crystal from Godkärra. The crystal is the dark grain in the top border. Euxenite from Godkärra. In feldspar, showing radiation damage.

Mineral class Oxides : Perovskite - Pyrochlore - Columbite group.

Chemical formula (Y,Er,Ce,U,Pb,Ca)(Nb,Ta,Ti)₂(O,OH)₆

Crystal system Orthorombic.

Habitus As short thick prismatic crystals. Also as derb masses.

Cleavage None, fracture brittle conchoidal.

Hardness 5.5-6.5

Density 4.3-5.9

Color Dark brown to black.

Streak Light brown.

Luster Metallic to vitreous.

Description A radioactive mineral, sometimes used as an ore of tantalum, terbium, Thulium.

Occurance In granitic pegmatites.

Associates Quartz, feldspar, columbite, tantalite, monazite.

Notes Radioactive.
Historial fact : Euxenite played an important role in the discovery of scandium, the 21:st element in the periodic system. (L. Scandia, Scandinavia)
On the basis of the Periodic System, Mendeleev predicted the existence of ekaboron in 1871, which would have an atomic weight between 40 of calcium and 48 of titanium.
The element was later discovered by Lars Nilson in 1878 in the minerals euxenite and gadolinite, which had not yet been found anywhere except in Scandinavia. By processing 10 kg of euxenite and other residues of rare-earth minerals, Nilson was able to prepare about 2g of highly pure scandium oxide. Later scientists pointed out that Nilson's scandium was identical with Mendeleev's ekaboron.

Euxenite was first described in 1870 by Scheerer.
Origin of name : From the Greek eu - "good" and xenos - "foreigner."

Locations A relatively rare mineral in Sweden.

Abborrselet quartz quarry, Jämtland. Rarely but in big crystal aggregates in red microcline.
Gräne feldspar quarry, Holsljunga, Älvsborgs län. Up to 2dm aggregates.
Slättåkra, Alseda, Småland. Sporadic.
Nols quartz-feldspar quarry, Nödinge, Västergötland. A classical locality.
Godkärra, Riddarhyttan, Västmanland. As small black crystals in feldspar with biotite and andalusite.
Arendal - Froland - Evje, Norway.
Iveland, Norway.
Aust-Jotunheimen, Norway.
Krødsherad, Norway.
Ural mountains, Russia.
Ampangabe, Madagascar.
Minas Gerais, Brasil.
White Tank mountains and Kingman quarries, Arizona. Encampment, Wyoming. Colorado. All in USA.
Quadeville and Madwaska, Ontario, Canada.

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Last changed : 1998-05-24

Mineral class	Oxides : Perovskite - Pyrochlore - Columbite group.
Chemical formula	(Y,Er,Ce,U,Pb,Ca)(Nb,Ta,Ti)₂(O,OH)₆
Crystal system	Orthorombic.
Habitus	As short thick prismatic crystals. Also as derb masses.
Cleavage	None, fracture brittle conchoidal.
Hardness	5.5-6.5
Density	4.3-5.9
Color	Dark brown to black.
Streak	Light brown.
Luster	Metallic to vitreous.
Description	A radioactive mineral, sometimes used as an ore of tantalum, terbium, Thulium.
Occurance	In granitic pegmatites.
Associates	Quartz, feldspar, columbite, tantalite, monazite.
Notes	Radioactive. Historial fact : Euxenite played an important role in the discovery of scandium, the 21:st element in the periodic system. (L. Scandia, Scandinavia) On the basis of the Periodic System, Mendeleev predicted the existence of ekaboron in 1871, which would have an atomic weight between 40 of calcium and 48 of titanium. The element was later discovered by Lars Nilson in 1878 in the minerals euxenite and gadolinite, which had not yet been found anywhere except in Scandinavia. By processing 10 kg of euxenite and other residues of rare-earth minerals, Nilson was able to prepare about 2g of highly pure scandium oxide. Later scientists pointed out that Nilson's scandium was identical with Mendeleev's ekaboron. Euxenite was first described in 1870 by Scheerer. Origin of name : From the Greek eu - "good" and xenos - "foreigner."
Locations	A relatively rare mineral in Sweden. Abborrselet quartz quarry, Jämtland. Rarely but in big crystal aggregates in red microcline. Gräne feldspar quarry, Holsljunga, Älvsborgs län. Up to 2dm aggregates. Slättåkra, Alseda, Småland. Sporadic. Nols quartz-feldspar quarry, Nödinge, Västergötland. A classical locality. Godkärra, Riddarhyttan, Västmanland. As small black crystals in feldspar with biotite and andalusite. Arendal - Froland - Evje, Norway. Iveland, Norway. Aust-Jotunheimen, Norway. Krødsherad, Norway. Ural mountains, Russia. Ampangabe, Madagascar. Minas Gerais, Brasil. White Tank mountains and Kingman quarries, Arizona. Encampment, Wyoming. Colorado. All in USA. Quadeville and Madwaska, Ontario, Canada.