Nickel mineralisation in the regolith, in the upper saprolite typically exists as goethite, hematite, limonite and is often associated with polydymite and violarite, nickel sulfides which are of supergene association.
en.wikipedia.org Its name is derived from the extensive deposits of limonite (iron ore) once mined here.
en.wikipedia.org In other cases quartz and iron oxides, limonite, goethite, and jarosite, exist as pseudomorphs replacing the pyrite and primary ore minerals.
en.wikipedia.org Two types of nickel ore are of commercial importance, limonite (oxide) ore and saprolite (nickel silicate) ore.
en.wikipedia.org Associated minerals include malachite, olivenite, quartz, limonite, adamite, azurite, and brochantite among others.
en.wikipedia.org