found in Northwest Africa
What is NWA 3118?
Carbonaceous chondrites contain some of the first materials that formed from our solar system. This dark rock has round to irregularly shaped chondrules and calcium-aluminum-rich inclusions (CAIs). Read more about CAIs on our Allende page here.
Chondrules are enigmatic creatures. Their composition, mineralogy, and texture give us clues into their origin story, but we are still trying to unlock all the pieces. Like all things scientific, they are classified based on the texture and mineralogy. Our sample NWA 3118 has glorious barred olivine chondrules, amoeboid olivine aggregates (AOAs), as well as the primitive CAIs.
The picture above is actually of the meteorite NWA 2086, which is ‘paired’ with NWA 3118 – the thin section we imaged. Because a meteor commonly explodes into multiple pieces in the atmosphere, similarly located ‘finds’ may be fragments of a single meteorite fall. After analyses are complete, meteorite classifiers can suggest a ‘pairing’ although there is always some degree of uncertainty.
Under the Microscope
In transmitted cross-polarized light, the colorful chondrules are what stands out against the carbonaceous matrix. With distinctly clear and unaltered chondrules, NWA 3118 doesn’t disappoint. There are multiple barred olivine chondrules both round and irregular shaped, which we highlight in some of our designs. Amoeboid olivine aggregates appear as colorful clusters of tiny olivine crystals. What’s your favorite chondrule in NWA 3118? We know we have our favorites!
Blog on Chondrules Coming Soon…