Coolidge, CL4

Coolidge is an unusual carbonaceous chondrite.  It was initially classified as a CV3.8, and was later reclassified by different researchers as…a type-3.8 ungrouped carbonaceous chondrite, a CV4 chondrite, and as a type-4 ungrouped carbonaceous chondrite.

Consensus is that Coolidge is similar to CV3s, but…slightly different.  Work by Kallemeyn et al., (1995) and Metzler et al., (2021) ultimately suggested that Coolidge and a few similar meteorites are distinct from other CV-chondrites and represent a new group of carbonaceous chondrites.

Coolidge is now one of the few described CL carbonaceous chondrites, although I believe a review of existing meteorites will likely reveal additional CL chondrites classified as CR2 and reduced CV3 chondrites.

The specimen pictured below was part of the collection of Dr. Donald Rathbun, a meteorite collector and hunter from El Paso, Texas.  Don was responsible for the recovery of a number of new meteorites from Mexico and the US, including Barrilla.

This slice weighs approximately 15.5 grams.  It still has its original American Meteorite Museum label, numbered 397.20.  The back of the label reads: This fall is especially rich in chondrules

 

This specimen was acquired from Nininger with several other American Meteorite Museum specimens, most likely while the Niningers were located at the American Meteorite Museum on Route 66, opposite Meteor Crater.