'Ulvöspinel' or ulvospinel is an iron titanium oxide mineral with formula: Fe
2TiO
4. It forms brown to black metallic
isometric crystals with a
Mohs hardness of 5.5 to 6. It belongs to the
spinel group of minerals, as does
magnetite, Fe
3O
4 .
Ulvospinel forms as solid solutions with magnetite at high temperatures and reducing conditions, and grains crystallized from some
basalt-
gabbro magmas are rich in the ulvospinel component. The ulvospinel component tends to oxidize to magnetite plus
ilmenite during subsolidus cooling of the host rocks, and the ilmenite so produced may form apparent
exsolution (trellis type) laminae in
magnetite. The texture was once interpreted as indicating solid solution between ilmenite and magnetite, until the oxidation reaction and resultant textures were reproduced in laboratory experiments first described by Buddington and Lindsley (1964, Journal of Petrology 5, p. 310-357). The results are important to
plate tectonics because magnetite is an important recorder of rock magnetism.
Ulvospinel was first described from a
dolerite layered intrusion in the Ulvö Islands, Ångermanland,
Sweden in 1943. The locality is an iron, titanium and vanadium mining area that has been active since the 17th century. It is common in titaniferous magnetite iron ore deposits. It also occurs in
kimberlites, in some reduced iron-bearing
basalts and is common in
lunar basalts
References
★ Mineral Data Publishing (2005) ''Ulvöspinel''
PDF Retrieved April 20, 2006
★
Webmineral data Accessed April 20, 2006
★
Mindat with location data Accessed April 20, 2006