Meteorite name : NWA 998 Type : Martian Meteorite, Nakhlite, SNC Country : North West Africa Date of find : Purchased september 2001 ? Tkw : 456g Northwest Africa 998 Purchased 2001 September Classification and mineralogy (A. Irving and S. Kuehner, UWS): a friable, dark green rock with minor orange-brown alteration products that probably are of pre-terrestrial origin. Composed mainly of subhedral, olive-green, complexly-zoned subcalcic augite (Fs22Wo39) with subordinate yellow olivine (Fa64), orthopyroxene (Fs49Wo4), interstitial plagioclase (Ab61Or4 containing 0.1 wt.% SrO, and exhibiting normal birefringence), titanomagnetite, chlorapatite and pyrrhotite. The overall texture is that of a hypabyssal, adcumulate igneous rock, and the apparent crystallization sequence is olivine, orthopyroxene, titanomagnetite, augite, apatite, plagioclase.