Editing Limonite (section)

==Uses==
[[File:Limonite concretion.jpg|thumb|upright|Limonite concretion from the [[spoil bank]] of a uranium mine]]
Nickel-rich limonite ores represent the largest reserves of nickel.  Such minerals are classified as [[lateritic nickel ore deposits]].<ref name="ullmann-1">{{Ullmann|author=Kerfoot, Derek G. E. |title=Nickel|doi=10.1002/14356007.a17_157|year=2005}}</ref>

One of the first uses was as a [[pigment]].  The yellow form produced yellow [[ochre]] for which [[Cyprus]] was famous,<ref>Constantinou, G. and Govett, G. J. S. (1972). "Genesis of sulphide deposits, ochre and umber of Cyprus". ''Transactions of the Institution of Mining and Metallurgy''. 81: pp. 34–46</ref> while the darker forms produced more earthy tones. Roasting the limonite changed it partially to hematite, producing red ochres, [[burnt umber]]s and [[sienna]]s.<ref>Heckel, George B. (1910) "Iron Oxide Paints". ''Paint, oil and drug review''. 50(4): pp. 14–21,  [https://books.google.com/books?id=7P9YAAAAYAAJ&pg=PA52 page 14]</ref> Bog iron ore and limonite mudstones are mined as a source of iron. 

''Iron caps'' or [[gossan]]s of siliceous iron oxide typically form as the result of intensive [[oxidation]] of [[sulfide]] ore deposits.<ref name="Brown">Brown, G. Chester (1915) ''Mines and mineral resources of Shasta county, Siskiyou county, Trinity county'' California State Mining Bureau, California State Printing Office, Sacramento, California, [https://books.google.com/books?id=WbpIAAAAMAAJ&pg=PA15 pages 15&ndash;16], {{OCLC|5458708}}</ref> These gossans were used by prospectors as guides to buried ore. 

Limonite was mined for its ancillary gold content. The oxidation of sulfide deposits which contained [[gold]], often resulted in the concentration of gold in the iron oxide and quartz of the gossans. The gold of the primary veins was concentrated into the limonites of the deeply weathered rocks. In another example the deeply weathered iron formations of [[Brazil]] served to concentrate gold with the limonite of the resulting soils.