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, US
General
Category	Native element mineral
Formula	Ni2Fe to Ni3Fe
IMA symbol	Awr[1]
Strunz classification	1.AE.20 Metals and intermetallic alloys
Dana classification	01.01.11.04 Iron–nickel group
Crystal system	Cubic
Crystal class	Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m)
Space group	Pm3m
Identification
Color	Silver-white to grayish white
Crystal habit	Massive; as pebbles, grains and flakes; rarely as crystals; as rims or regular intergrowths with kamacite in meteorites
Tenacity	Malleable and flexible
Mohs scale hardness	5.5–6
Luster	Metallic
Diaphaneity	Opaque
Specific gravity	7.8–8.65
Other characteristics	Strongly 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 was examined 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]