NWA 998 is an anomalous Martian orthopyroxene-bearing nakhlite meteorite found in the year 2001. Anomalous, when describing this meteorite, means it is a one-of-a-kind find. It is different from the other known nakhlites. Some of the unique features are it is the first nakhlite found to contain discrete crystals of orthopyroxene, the major component of the worlds most famous meteorite ALH 84001. Like ALH 84001, which at one time was sub-classed under nakhlites, ankertitic and other carbonates have been identified in this meteorite and are pre-terrestrial in origin. These carbonates were deposited in this meteorite when underground water flowed through it beneath the surface of Mars. Another feature is the existence of simplectites, structures that will tell us more about the geology of Mars. These simplectites were believed to be formed when a secondary post crystallization event occurred on Mars involving a super heated liquid (water) that chemically altered parts of this rock. If this were not enough, this meteorite contains minerals believed to be created by extraterrestrial weathering. Several other unique features are being explored and if proven true will lead to a new way of thinking about these rare rocks. Expect to hear a lot more in the news about this most scientifically important find.
The only material I have available is the 1-gram vial of fragments listed here!
Article about NWA 998:
Hupé, G.M., (2002) Quest for Planetary meteorites (article).
Click here to read about our aquisition of NWA 998
Lab analysis at the University of Central Florida:
Click here to see some iimages of NWA 998 on my Expeditions & Adventures page.
Meteoritical Bulletin entry for NWA 998:
Click here for the Official classification of NWA 998