Ulvöspinel: Difference between revisions

| image = Ulvöspinel-522694.jpg

|IMAsymbol=Uspl| strunz = 044.BB.05

| system = [[Isometric -crystal hexoctahedral(4/m 3 2/m)system|Cubic]]

| mohs = 5.5 -– 6.0

| references = <ref>http://www.mindat.org/show.php?id=4089 Mindat</ref><ref>http://rruff.geo.arizona.edu/doclib/hom/ulvospinel.pdf Handbook of Mineralogy</ref><ref>http://webmineral.com/data/Ulvospinel.shtml Webmineral data</ref><ref>https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Ulv%F6spinel Mineralienatlas</ref>

'''Ulvöspinel''' or '''ulvite''' is an iron titanium oxide mineral with formula: [[iron|Fe]]₂[[titanium|Ti]][[oxygen|O]]₄or TiFe²⁺₂O₄. It forms brown to black metallic [[Cubic (crystal system)|isometric]] crystals with a [[Mohs hardness]] of 5.5 to 6. It belongs to the [[spinel]] group]] of minerals, as does [[magnetite]], Fe₃O₄.

Ulvöspinel forms as [[solid solutionssolution]]s with magnetite at high temperatures and reducing conditions, and grains crystallized from some [[basalt]]-[[gabbro]] magmas are rich in the ulvöspinel component. The ulvöspinel 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.&nbsp;310-357310–357). The results are important to [[plate tectonics]] because magnetite is an important recorder of rock magnetism.

Ulvöspinel was first described}}</ref> 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.<ref>{{cite journal | doi = 10.1080/11035894609446484| title = A ferro-ortho-titanate ore from Södra Ulvön| journal = Geologiska Föreningen i Stockholm Förhandlingar| volume = 68| issue = 4| pages = 578–587| year = 1946| last1 = Mogensen| first1 = Fredrik}}</ref> It is common in titaniferous magnetite iron ore deposits. It also occurs in [[kimberlite]]s, in some reduced iron-bearing [[basalt]]s and is common in [[moon|lunar]] basalts.