Millerite is a nickelsulfide mineral, NiS. It is brassy in colour and has an acicular habit, often forming radiating masses and furry aggregates. It can be distinguished from pentlandite by crystal habit, its duller colour, and general lack of association with pyrite or pyrrhotite.
Millerite is a common metamorphic mineral replacing pentlandite within serpentiniteultramafics. It is formed in this way by removal of sulfur from pentlandite or other nickeliferous sulfide minerals during metamorphism or metasomatism.
Millerite is also formed from sulfur poor olivinecumulates by nucleation. Millerite is thought to form from sulfur and nickel which exist in pristine olivine in trace amounts, and which are driven out of the olivine during metamorphic processes. Magmatic olivine generally has up to ~4000 ppm Ni and up to 2500 ppm S within the crystal lattice, as contaminants and substituting for other transition metals with similar ionic radii (Fe2+ and Mn2+).[citation needed]
Millerite structure
During metamorphism, sulfur and nickel within the olivine lattice are reconstituted into metamorphic sulfide minerals, chiefly millerite, during serpentinization and talc carbonate alteration. When metamorphic olivine is produced, the propensity for this mineral to resorb sulfur, and for the sulfur to be removed via the concomitant loss of volatiles from the serpentinite, tends to lower sulfur fugacity.
This forms disseminated needle like millerite crystals dispersed throughout the rock mass.
Millerite may be associated with heazlewoodite and is considered a transitional stage in the metamorphic production of heazlewoodite via the above process.
Economic importance
Millerite, when found in enough concentration, is a very important ore of nickel because, for its mass as a sulfide mineral, it contains a higher percentage of nickel than pentlandite. This means that, for every percent of millerite, an ore contains more nickel than an equivalent percentage of pentlandite sulfide.
Millerite forms an important ore constituent of the Silver Swan, Wannaway, Cliffs, Honeymoon Well, Yakabindie and Mt Keith (MKD5) orebodies. It is an accessory mineral associated with nickel laterite deposits in New Caledonia.
Occurrence
Lustrous mass of intergrown millerite needles from Kalgoorlie, Western Australia. (size: 3.9 x 3.5 x 2.2 cm)
Millerite is found as a metamorphic replacement of pentlandite within the Silver Swan nickel deposit, Western Australia, and throughout the many ultramafic serpentinite bodies of the Yilgarn Craton, Western Australia, generally as a replacement of metamorphosed pentlandite. There is one known occurrence of millerite in South Africa, near Pafuri in the Transvaal. The deposit has never been commercially mined.[7]
^Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 279-280, ISBN0-471-80580-7
^"Millerite". Cape Minerals. Retrieved 7 February 2017.
^Geiger, T.; Bischoff, A. (1995). "Formation of opaque minerals in CK chondrites". Planetary and Space Science. 43 (3–4): 485–498. Bibcode:1995P&SS...43..485G. doi:10.1016/0032-0633(94)00173-O.
External links
Wikimedia Commons has media related to Millerite.
May 04, 2023
millerite, nickel, sulfide, more, generally, nickel, sulfide, religious, movement, millerism, neighborhood, gary, miller, beach, nickel, sulfide, mineral, brassy, colour, acicular, habit, often, forming, radiating, masses, furry, aggregates, distinguished, fro. For nickel sulfide more generally see Nickel sulfide For the religious movement see Millerism For the neighborhood in Gary see Miller Beach Millerite is a nickel sulfide mineral NiS It is brassy in colour and has an acicular habit often forming radiating masses and furry aggregates It can be distinguished from pentlandite by crystal habit its duller colour and general lack of association with pyrite or pyrrhotite MilleriteGeneralCategorySulfide mineralFormula repeating unit NiSIMA symbolMlr 1 Strunz classification2 CC 20Crystal systemTrigonalCrystal classDitrigonal pyramidal 3m same H M symbol Space groupR3mUnit cella 9 607 A c 3 143 A Z 9IdentificationColourPale brass yellow to bronze yellow tarnishes to iridescenceCrystal habitTypically acicular needle like often in radial sprays also massiveCleavagePerfect on 101 1 and 011 2 obscured by typical formFractureUnevenTenacityBrittle capillary crystals elasticMohs scale hardness3 3 5LusterMetallicStreakGreenish blackDiaphaneityOpaqueSpecific gravity5 3 5 5Other characteristicsbrittle and becomes magnetic on heatingReferences 2 3 4 5 6 Contents 1 Paragenesis 2 Economic importance 3 Occurrence 4 See also 5 References 6 External linksParagenesis EditMillerite is a common metamorphic mineral replacing pentlandite within serpentinite ultramafics It is formed in this way by removal of sulfur from pentlandite or other nickeliferous sulfide minerals during metamorphism or metasomatism Millerite is also formed from sulfur poor olivine cumulates by nucleation Millerite is thought to form from sulfur and nickel which exist in pristine olivine in trace amounts and which are driven out of the olivine during metamorphic processes Magmatic olivine generally has up to 4000 ppm Ni and up to 2500 ppm S within the crystal lattice as contaminants and substituting for other transition metals with similar ionic radii Fe2 and Mn2 citation needed Millerite structure During metamorphism sulfur and nickel within the olivine lattice are reconstituted into metamorphic sulfide minerals chiefly millerite during serpentinization and talc carbonate alteration When metamorphic olivine is produced the propensity for this mineral to resorb sulfur and for the sulfur to be removed via the concomitant loss of volatiles from the serpentinite tends to lower sulfur fugacity This forms disseminated needle like millerite crystals dispersed throughout the rock mass Millerite may be associated with heazlewoodite and is considered a transitional stage in the metamorphic production of heazlewoodite via the above process Economic importance EditMillerite when found in enough concentration is a very important ore of nickel because for its mass as a sulfide mineral it contains a higher percentage of nickel than pentlandite This means that for every percent of millerite an ore contains more nickel than an equivalent percentage of pentlandite sulfide Millerite forms an important ore constituent of the Silver Swan Wannaway Cliffs Honeymoon Well Yakabindie and Mt Keith MKD5 orebodies It is an accessory mineral associated with nickel laterite deposits in New Caledonia Occurrence Edit Lustrous mass of intergrown millerite needles from Kalgoorlie Western Australia size 3 9 x 3 5 x 2 2 cm Millerite needles partially encased in calcite and oxidized to zaratite on their surfaces from the Devonian Milwaukee Formation of Wisconsin Millerite is found as a metamorphic replacement of pentlandite within the Silver Swan nickel deposit Western Australia and throughout the many ultramafic serpentinite bodies of the Yilgarn Craton Western Australia generally as a replacement of metamorphosed pentlandite There is one known occurrence of millerite in South Africa near Pafuri in the Transvaal The deposit has never been commercially mined 7 It is commonly found as radiating clusters of acicular needle like crystals in cavities in sulfide rich limestone and dolomite or in geodes It is also found in nickel iron meteorites such as CK carbonaceous chondrites 8 Millerite was discovered by Wilhelm Haidinger in 1845 in the coal mines of Wales It was named for British mineralogist William Hallowes Miller The mineral is quite rare in specimen form and the most common source of the mineral is in the Halls Gap area of Lincoln County Kentucky in the United States See also EditList of minerals List of minerals named after people Nickel Mines PennsylvaniaReferences Edit Warr L N 2021 IMA CNMNC approved mineral symbols Mineralogical Magazine 85 3 291 320 Bibcode 2021MinM 85 291W doi 10 1180 mgm 2021 43 S2CID 235729616 Mineralienatlas http rruff geo arizona edu doclib hom millerite pdf Handbook of Mineralogy http www mindat org min 2711 html Mindat http webmineral com data Millerite shtml Webmineral Hurlbut Cornelius S Klein Cornelis 1985 Manual of Mineralogy 20th ed pp 279 280 ISBN 0 471 80580 7 Millerite Cape Minerals Retrieved 7 February 2017 Geiger T Bischoff A 1995 Formation of opaque minerals in CK chondrites Planetary and Space Science 43 3 4 485 498 Bibcode 1995P amp SS 43 485G doi 10 1016 0032 0633 94 00173 O External links Edit Wikimedia Commons has media related to Millerite Mineral galleries Wisconsin minerals University of Kentucky Kentucky Geological Survey Sulfide Minerals Retrieved from https en wikipedia org w index php title Millerite amp oldid 1136186484, wikipedia, wiki, book, books, library,
