Kambaldaite
Encyclopedia
Kambaldaite, NaNi43(OH)3·3H2O, is an extremely rare hydrated sodium
nickel
carbonate mineral described from gossan
ous material associated with Kambalda type komatiitic nickel ore deposits
at Kambalda, Western Australia
, and Widgie Townsite nickel gossan, Widgiemooltha, Western Australia
.
Kambaldaite crystallises in the hexagonal system, is light green to blue and forms drusy to mammillated encrustations on the matrix.
Kambaldaite was first described in 1985 from the gossan of the Otter Shoot nickel orebody, Kambalda, during mining of the gossanous material. Kambaldaite, though in lesser and rarer amount, is also found in the Widgiemooltha nickel gossans, probably discovered there in the early to mid 1990s.
as a supergene
alteration mineral of nickel sulfide minerals, in arid or semi-arid environments which produce conditions amenable to concentration of calcareous or carbonate minerals in the weathering profile.
Kambaldaite from Kambalda and Widgiemooltha is associated with komatiite
-associated nickel sulfide gossans and is probably formed by substitution of nickel into carbonates such as magnesite
which are formed by oxidation of the lithology, and oxidation of primary and supergene nickel sulfide minerals.
Kambaldaite is formed from a similar process to the weathering of other sulfide minerals to form carbonate minerals. The sulfide minerals which are weathered to produce kambaldaite are pentlandite
, violarite
, millerite
and rarely nickeline.
, malachite
, annabergite
, gaspeite
and magnesite
in the nickel sulfide gossans of Kambalda and Widgiemooltha. It is not known from other nickel sulfide gossans within the Yilgarn Craton
, potentially due to many of these existing within areas of laterite
cover, deeper regolith
development or less favorable rainfall conditions.
Kambaldaite is not reported from the Tasmania
n or New South Wales
nickel carbonate occurrences because it is a supergene
carbonate mineral and not a hydrothermal mineral.
Kambaldaite is also reported from the Inn Valley, North Tyrol, Austria
, and from Linopolis, Minas Gerais
, Brazil
.
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
carbonate mineral described from gossan
Gossan
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein. In the classic gossan or iron cap all that remains is iron oxides and quartz often in the form of boxworks, quartz lined cavities retaining the shape of the dissolved...
ous material associated with Kambalda type komatiitic nickel ore deposits
Kambalda type komatiitic nickel ore deposits
Kambalda type nickel ore deposits are a class of magmatic nickel-copper ore deposit in which the physical processes of komatiite volcanology serve to enrich, concentrate and deposit nickel-bearing sulfide within the lava flow environment of an erupting komatiite volcano.-Classification:The...
at Kambalda, Western Australia
Kambalda, Western Australia
Kambalda is a small mining town about 60 kilometres from the mining city of Kalgoorlie in Western Australia, within the Goldfields. It is split into two townsites 4 kilometres apart, Kambalda East and Kambalda West; and is located on the western edge of a giant salt lake, Lake Lefroy...
, and Widgie Townsite nickel gossan, Widgiemooltha, Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
.
Kambaldaite crystallises in the hexagonal system, is light green to blue and forms drusy to mammillated encrustations on the matrix.
Kambaldaite was first described in 1985 from the gossan of the Otter Shoot nickel orebody, Kambalda, during mining of the gossanous material. Kambaldaite, though in lesser and rarer amount, is also found in the Widgiemooltha nickel gossans, probably discovered there in the early to mid 1990s.
Paragenesis
Kambaldaite is formed in the regolithRegolith
Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...
as a supergene
Supergene (geology)
In ore deposit geology, supergene processes or enrichment occur relatively near the surface. Supergene processes include the predominance of meteoric water circulation with concomitant oxidation and chemical weathering. The descending meteoric waters oxidize the primary sulfide ore minerals and...
alteration mineral of nickel sulfide minerals, in arid or semi-arid environments which produce conditions amenable to concentration of calcareous or carbonate minerals in the weathering profile.
Kambaldaite from Kambalda and Widgiemooltha is associated with komatiite
Komatiite
Komatiite is a type of ultramafic mantle-derived volcanic rock. Komatiites have low silicon, potassium and aluminium, and high to extremely high magnesium content...
-associated nickel sulfide gossans and is probably formed by substitution of nickel into carbonates such as magnesite
Magnesite
Magnesite is magnesium carbonate, MgCO3. Iron substitutes for magnesium with a complete solution series with siderite, FeCO3. Calcium, manganese, cobalt, and nickel may also occur in small amounts...
which are formed by oxidation of the lithology, and oxidation of primary and supergene nickel sulfide minerals.
Kambaldaite is formed from a similar process to the weathering of other sulfide minerals to form carbonate minerals. The sulfide minerals which are weathered to produce kambaldaite are pentlandite
Pentlandite
Pentlandite is an iron-nickel sulfide, 9S8. Pentlandite usually has a Ni:Fe ratio of close to 1:1. It also contains minor cobalt.Pentlandite forms isometric crystals, but is normally found in massive granular aggregates. It is brittle with a hardness of 3.5 - 4 and specific gravity of 4.6 - 5.0 and...
, violarite
Violarite
Violarite is a supergene sulfide mineral associated with the weathering and oxidation of primary pentlandite nickel sulfide ore minerals....
, millerite
Millerite
Millerite is a nickel sulfide mineral, NiS. It is brassy in colour and has an acicular habit, often forming radiating masses and furry aggregates...
and rarely nickeline.
Occurrence
Kambaldaite is associated with goethiteGoethite
Goethite , named after the German polymath Johann Wolfgang von Goethe, is an iron bearing oxide mineral found in soil and other low-temperature environments. Goethite has been well known since prehistoric times for its use as a pigment. Evidence has been found of its use in paint pigment samples...
, malachite
Malachite
Malachite is a copper carbonate mineral, with the formula Cu2CO32. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses. Individual crystals are rare but do occur as slender to acicular prisms...
, annabergite
Annabergite
Annabergite is an arsenate mineral consisting of a hydrous nickelarsenate, Ni32·8H2O, crystallizing in the monoclinic system and isomorphous with vivianite and erythrite. Crystals are minute and capillary and rarely met with, the mineral occurring usually as soft earthy masses and encrustations. A...
, gaspeite
Gaspeite
Gaspeite is an extremely rare nickel carbonate mineral named for the place it was first described, in the Gaspé Peninsula, Canada.Gaspeite's formula is CO3 and it is a bright green mineral. It forms massive to reniform pappillary aggregates in fractures, bottryoidal concretions in laterite or...
and magnesite
Magnesite
Magnesite is magnesium carbonate, MgCO3. Iron substitutes for magnesium with a complete solution series with siderite, FeCO3. Calcium, manganese, cobalt, and nickel may also occur in small amounts...
in the nickel sulfide gossans of Kambalda and Widgiemooltha. It is not known from other nickel sulfide gossans within the Yilgarn Craton
Yilgarn craton
The Yilgarn Craton is a large craton which constitutes the bulk of the Western Australian land mass. It is bounded by a mixture of sedimentary basins and Proterozoic fold and thrust belts...
, potentially due to many of these existing within areas of laterite
Laterite
Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock...
cover, deeper regolith
Regolith
Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...
development or less favorable rainfall conditions.
Kambaldaite is not reported from the Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
n or New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
nickel carbonate occurrences because it is a supergene
Supergene (geology)
In ore deposit geology, supergene processes or enrichment occur relatively near the surface. Supergene processes include the predominance of meteoric water circulation with concomitant oxidation and chemical weathering. The descending meteoric waters oxidize the primary sulfide ore minerals and...
carbonate mineral and not a hydrothermal mineral.
Kambaldaite is also reported from the Inn Valley, North Tyrol, Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
, and from Linopolis, Minas Gerais
Minas Gerais
Minas Gerais is one of the 26 states of Brazil, of which it is the second most populous, the third richest, and the fourth largest in area. Minas Gerais is the Brazilian state with the largest number of Presidents of Brazil, the current one, Dilma Rousseff, being one of them. The capital is the...
, Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
.