Northwest Africa 1756 was purchased by an
American dealer while inspecting meteorites on offer by a nomad
in the village of Safsaf during October, 2002. The stone was a
tiny 68.2g individual and since then, no other paired stones
have been found. NWA 1756 was later classified as an ordinary
chondrite LL3.0/3.2 Monomict Breccia with a Shock Rating of S1
and a Weathering Level of W1-2 (lightly weathered). It should
also be noted that a xenolithic inclusion in this meteorite was found to have a
Shock Rating of S4.
At the time, NWA 1756 was an exceptionally
exciting find due to it's extremely primitive nature. In fact it
was compared to the Semarkona meteorite which is often
considered the benchmark for primitive chondrites. However NWA
1756 was later reclassified in 2005 by Grossman and Brearley who
developed a more accurate technique for classifying primitive
chondrites under 3.2. So using the new classification scheme,
the officially recommended classification now stands at LL3.10
still making this one of the most primitive ordinary chondrites
ever found. So while there are now a few more primitive
chondrites similar to NWA 1756, it will always be remembered as
the first truly unmetamorphosed chondrite available to
collectors and one of the benchmarks others were later measured
against. The 2.0g Endcut below is part of the Meteorites Australia Collection (MA.05.0070).