degree of disorder = 11%, Curie point = 550°C, magnetic moment = 4.6 μB, Suessite is a rare iron silicide mineral with chemical formula: Fe3Si.

It was discovered in 1982 during the chemical analysis of The North Haig olivine pigeonite achondrite (ureilite).

It is a cream white color in reflected light, and ranges in size from 1 μm "blebs" to elongated grains that can reach up to 0.45 cm in length.

When Keil, Fuchs, and Berkley first discovered the mineral they described it as having a relatively low optical relief, but there was no determination of the index of refraction.

[12] The other natural iron silicides include gupeiite (Fe3Si), hapkeite (Fe2Si), linzhiite (FeSi2), luobusaite (Fe0.84Si2), naquite (FeSi), xifengite (Fe5Si3), and zangboite (TiFeSi2).