Awaruite

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

Awaruite
Awaruite pebble from Josephine County, Oregon, USA
General
CategoryNative element mineral
Formula
(repeating unit)		Ni2Fe to Ni3Fe
IMA symbolAwr[1]
Strunz classification1.AE.20
Metals and intermetallic alloys
Dana classification01.01.11.04
Iron - nickel group
Crystal systemCubic
Crystal classHexoctahedral (m3m)
H-M symbol: (4/m 3 2/m)
Space groupPm3m
Identification
ColorSilver-white to grayish white
Crystal habitMassive; as pebbles, grains and flakes; rarely as crystals; as rims or regular intergrowths with kamacite in meteorites
TenacityMalleable and flexible
Mohs scale hardness5.5 -6
LusterMetallic
DiaphaneityOpaque
Specific gravity7.8–8.65
Other characteristicsStrongly magnetic
References[2][3][4]

Awaruite occurs in river placer deposits derived from serpentinized peridotites and ophiolites. It also occurs as a rare component of meteorites. It occurs in association with native gold and magnetite in placers; with copper, heazlewoodite, pentlandite, violarite, chromite, and millerite in peridotites; with kamacite, allabogdanite, schreibersite and graphite in meteorites.[2]

It was first described in 1885 for an occurrence along Gorge River, near Awarua Bay, South Island, New Zealand, its type locality.[2][3]

Awaruite is also known as josephinite in an occurrence in Josephine County, Oregon where it is found as placer nuggets in stream channels and masses in serpentinized portions of the Josephine peridotite. Some nuggets contain andradite garnet.[5]

An occurrence of awaruite is being developed commercially as an ore mineral in a large low grade deposit in central British Columbia, some 90 km northwest of Fort St. James. In the deposit awaruite occurs disseminated in the Mount Sidney Williams ultramafic/ophiolite complex.[6]

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/awaruite.pdf Handbook of Mineralogy
  3. http://www.mindat.org/min-439.html Mindat.org
  4. http://www.webmineral.com/data/Awaruite.shtml Webmineral data
  5. John M. Bird and Maura S. Weathers, Origin of josephinite, Geochemical Journal, Vol. 13, pp. 41 to 55, 1979
  6. FPX Nickel Confirms Anticipated Timing for Completion of Preliminary Economic Assessment on Baptiste Nickel Deposit
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