Heazlewoodite

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Heazlewoodite
Hellyerite-Heazlewoodite-Zaratite-255031.jpg
Zaratite (emerald-green coating), hellyerite (powder-blue) and heazlewoodite (light bronze)
General
Category Sulfide mineral
Formula
(repeating unit)
Ni3S2
IMA symbol Hzl [1]
Strunz classification 2.BB.05
Crystal system Trigonal
Crystal class Trapezohedral (32)
H-M symbol: (32)
Space group R32
Identification
ColorPale bronze
Crystal habit Disseminated granular to massive
Twinning Possibly the cause of mosaic structure seen in polished section
Cleavage None
Mohs scale hardness4
Luster Metallic
Diaphaneity Opaque
Specific gravity 5.82
Optical propertiesAnisotropy – Strong, brown to bluish gray
References [2] [3] [4]

Heazlewoodite, Ni3S2, is a rare sulfur-poor nickel sulfide mineral found in serpentinitized dunite. It occurs as disseminations and masses of opaque, metallic light bronze to brassy yellow grains which crystallize in the trigonal crystal system. It has a hardness of 4, a specific gravity of 5.82. Heazlewoodite was first described in 1896 from Heazlewood, Tasmania, Australia. [4]

Contents

Paragenesis

Heazlewoodite is formed within terrestrial rocks by metamorphism of peridotite and dunite via a process of nucleation. Heazlewoodite is the least sulfur saturated of nickel sulfide minerals and is only formed via metamorphic exsolution of sulfur from the lattice of metamorphic olivine.

Heazlewoodite 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 (Fe 2+ and Mg 2+).

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.

In this environment, nickel sulfide mineralogy converts to the lowest-sulfur state available, which is heazlewoodite.

Occurrence

Heazlewoodite is known from few ultramafic intrusions within terrestrial rocks. The Honeymoon Well ultramafic intrusive, Western Australia is known to contain heazlewoodite-millerite sulfide assemblages within serpentinized olivine adcumulate dunite, formed from the metamorphic process.

The mineral is also reported, again in association with millerite, from the ultramafic rocks of New Caledonia.

This mineral has been found in meteorites [5] including irons [6] and CV carbonaceous chondrites. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Pentlandite</span> Iron–nickel sulfide

Pentlandite is an iron–nickel sulfide with the chemical formula (Fe,Ni)9S8. Pentlandite has a narrow variation range in nickel to iron ratios (Ni:Fe), but it is usually described as 1:1. In some cases, this ratio is skewed by the presence of pyrrhotite inclusions. It also contains minor cobalt, usually at low levels as a fraction of weight.

<span class="mw-page-title-main">Dunite</span> Ultramafic and ultrabasic rock from Earths mantle which is made of the mineral olivine

Dunite, also known as olivinite, is an intrusive igneous rock of ultramafic composition and with phaneritic (coarse-grained) texture. The mineral assemblage is greater than 90% olivine, with minor amounts of other minerals such as pyroxene, chromite, magnetite, and pyrope. Dunite is the olivine-rich endmember of the peridotite group of mantle-derived rocks.

<span class="mw-page-title-main">Serpentine subgroup</span> Group of phyllosilicate minerals

Serpentine subgroup are greenish, brownish, or spotted minerals commonly found in serpentinite. They are used as a source of magnesium and asbestos, and as decorative stone. The name comes from the greenish colour and smooth or scaly appearance from the Latin serpentinus, meaning "serpent rock".

<span class="mw-page-title-main">Chondrite</span> Class of stony meteorites made of round grains

A chondrite is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%.

<span class="mw-page-title-main">Peridotite</span> Coarse-grained ultramafic igneous rock type

Peridotite ( PERR-ih-doh-tyte, pə-RID-ə-) is a dense, coarse-grained igneous rock consisting mostly of the silicate minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than 45% silica. It is high in magnesium (Mg2+), reflecting the high proportions of magnesium-rich olivine, with appreciable iron. Peridotite is derived from Earth's mantle, either as solid blocks and fragments, or as crystals accumulated from magmas that formed in the mantle. The compositions of peridotites from these layered igneous complexes vary widely, reflecting the relative proportions of pyroxenes, chromite, plagioclase, and amphibole.

<span class="mw-page-title-main">Forsterite</span> Magnesium end-member of olivine, a nesosilicate mineral

Forsterite (Mg2SiO4; commonly abbreviated as Fo; also known as white olivine) is the magnesium-rich end-member of the olivine solid solution series. It is isomorphous with the iron-rich end-member, fayalite. Forsterite crystallizes in the orthorhombic system (space group Pbnm) with cell parameters a 4.75 Å (0.475 nm), b 10.20 Å (1.020 nm) and c 5.98 Å (0.598 nm).

<span class="mw-page-title-main">Ultramafic rock</span> Type of igneous and meta-igneous rock

Ultramafic rocks are igneous and meta-igneous rocks with a very low silica content, generally >18% MgO, high FeO, low potassium, and are composed of usually greater than 90% mafic minerals. The Earth's mantle is composed of ultramafic rocks. Ultrabasic is a more inclusive term that includes igneous rocks with low silica content that may not be extremely enriched in Fe and Mg, such as carbonatites and ultrapotassic igneous rocks.

<span class="mw-page-title-main">Serpentinization</span> Formation of serpentinite by hydration and metamorphic transformation of olivine

Serpentinization is a hydration and metamorphic transformation of ferromagnesian minerals, such as olivine and pyroxene, in mafic and ultramafic rock to produce serpentinite. Minerals formed by serpentinization include the serpentine group minerals, brucite, talc, Ni-Fe alloys, and magnetite. The mineral alteration is particularly important at the sea floor at tectonic plate boundaries.

<span class="mw-page-title-main">Anthophyllite</span> Silicate amphibole mineral

Anthophyllite is an orthorhombic amphibole mineral: ☐Mg2Mg5Si8O22(OH)2 (☐ is for a vacancy, a point defect in the crystal structure), magnesium iron inosilicate hydroxide. Anthophyllite is polymorphic with cummingtonite. Some forms of anthophyllite are lamellar or fibrous and are classed as asbestos. The name is derived from the Latin word anthophyllum, meaning clove, an allusion to the most common color of the mineral. The Anthophyllite crystal is characterized by its perfect cleavage along directions 126 degrees and 54 degrees.

<span class="mw-page-title-main">Trevorite</span>

Trevorite is a rare nickel iron oxide mineral belonging to the spinel group. It has the chemical formula NiFe3+2O4. It is a black mineral with the typical spinel properties of crystallising in the cubic system, black streaked, infusible and insoluble in most acids.

<span class="mw-page-title-main">Komatiite</span> Ultramafic mantle-derived volcanic rock

Komatiite is a type of ultramafic mantle-derived volcanic rock defined as having crystallised from a lava of at least 18 wt% magnesium oxide (MgO). It is classified as a 'picritic rock'. Komatiites have low silicon, potassium and aluminium, and high to extremely high magnesium content. Komatiite was named for its type locality along the Komati River in South Africa, and frequently displays spinifex texture composed of large dendritic plates of olivine and pyroxene.

<span class="mw-page-title-main">Hellyerite</span> Carbonate mineral

Hellyerite, NiCO3·6(H2O), is an hydrated nickel carbonate mineral. It is light blue to bright green in colour, has a hardness of 2.5, a vitreous luster, a white streak and crystallises in the monoclinic system. The crystal habit is as platy and mammillary encrustations on its matrix.

Kambalda type komatiitic nickel ore deposits are a class of magmatic iron-nickel-copper-platinum-group element ore deposit in which the physical processes of komatiite volcanology serve to deposit, concentrate and enrich a Fe-Ni-Cu-(PGE) sulfide melt within the lava flow environment of an erupting komatiite volcano.

Talc carbonates are a suite of rock and mineral compositions found in metamorphosed ultramafic rocks.

<span class="mw-page-title-main">Gaspéite</span> Nickel carbonate mineral

Gaspéite, a very rare nickel carbonate mineral, with the formula (Ni,Fe,Mg)CO3, is named for the place it was first described, in the Gaspé Peninsula, Québec, Canada.

<span class="mw-page-title-main">Awaruite</span>

Awaruite is a naturally occurring alloy of nickel and iron with a composition from Ni2Fe to Ni3Fe.

The Merlis Serpentinites are an aligned group of small serpentinite outcrops in the northwestern French Massif Central. Their parent rocks were peridotites from the upper mantle.

<span class="mw-page-title-main">Valleriite</span> Uncommon sulfide-hydroxide mineral of iron and copper

Valleriite is an uncommon sulfide mineral (hydroxysulfide) of iron and copper with formula: 4(Fe,Cu)S·3(Mg,Al)(OH)2 or (Fe2+,Cu)4(Mg,Al)3S4(OH,O)6. It is an opaque, soft, bronze-yellow to brown mineral which occurs as nodules or encrustations.

<span class="mw-page-title-main">Pecoraite</span> Nickel phyllosilicate mineral of the serpentine group

Pecoraite is a nickel silicate mineral and a member of the serpentine group. It was named after geologist William Thomas Pecora. It is monoclinic and has a chemical composition of Ni3(Si2O5)(OH)4. It is associated with the weathering-and-or oxidation of meteorites or nickel sulfide minerals such as millerite. It is also found in altered ultramafic rocks. Pecoraite is typically a green, lime green, or bluegreen mineral with a waxy, or earthy luster and a mohs hardness of 2.5. Common textural habits associated with pecoraite are curved plates, spirals and tubes. It can also be granular and massive.

<span class="mw-page-title-main">Millerite</span> Nickel sulfide mineral

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.

References

  1. 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.
  2. http://rruff.geo.arizona.edu/doclib/hom/heazlewoodite.pdf Handbook of Mineralogy
  3. http://webmineral.com/data/Heazlewoodite.shtml Webmineral data
  4. 1 2 http://www.mindat.org/min-1839.html Mindat
  5. Rubin, Alan E. (1997). "Mineralogy of meteorite groups". Meteoritics. 32 (2): 231–247. Bibcode:1997M&PS...32..231R. doi: 10.1111/j.1945-5100.1997.tb01262.x .
  6. Buchwald, V. F. (Sep 1977). "The Mineralogy of Iron Meteorites". Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences. 286 (1336): 453–491. Bibcode:1977RSPTA.286..453B. doi:10.1098/rsta.1977.0127. ISSN   0080-4614. S2CID   56064934.
  7. Mcsween Jr., Harry Y. (Dec 1977). "Petrographic variations among carbonaceous chondrites of the Vigarano type". Geochimica et Cosmochimica Acta. 41 (12): 1777–1790. Bibcode:1977GeCoA..41.1777M. doi:10.1016/0016-7037(77)90210-1.