Xifengite

Xifengite (Fe₅Si₃) is a rare metallic iron silicide mineral. The crystal system of xifengite is hexagonal. It has a specific gravity of 6.45 and a Mohs hardness of 5.5. It occurs as steel gray inclusions within other meteorite derived nickel iron mineral phases.

Xifengite
General
Category	Native element minerals
Formula	Fe5Si3
IMA symbol	Xif[1]
Strunz classification	1.BB.40
Crystal system	Hexagonal
Crystal class	Dihexagonal dipyramidal (6/mmm) H-M symbol: (6/m 2/m 2/m)
Space group	P63/mcm
Unit cell	a = 6.759(5) c = 4.720(5) [Å]; Z = 2
Identification
Color	Gray, steel-black
Crystal habit	As inclusions
Mohs scale hardness	5
Luster	Metallic
Streak	Black
Diaphaneity	Opaque
References	[2][3]

It was first described in 1984 and named for the eastern passageway, Xifengkou, of the Great Wall of China. The type locality is the Yanshan meteorite of the Hebei Province, China. It has also been reported from dredgings along the East Pacific Rise.

The other known natural iron silicide minerals are gupeiite (Fe₃Si), hapkeite (Fe₂Si), linzhiite (FeSi₂), luobusaite (Fe_0.84Si₂), naquite (FeSi), suessite ((Fe,Ni)₃Si), and zangboite (TiFeSi₂).^[4]

See also

• Glossary of meteoritics