Recommended classes in the Meteoritical Bulletin Database are assigned by the database editor. In most cases, this is based on the most recent classification that appears in either the Catalogue of Meteorites, MetBase, the US Antarctic Meteorite Newsletter, the Japanese Meteorite Newsletter, or the Meteoritical Bulletin. However, in a few cases it reflects differences of opinion about the proper way to classify the meteorite. The nomenclature used may also be modified by the editor to conform to an internally consistent classification scheme
The recommended classification C2-ung means:
"A carbonaceous chondrite of petrologic type 2 that is ungrouped."
The highlighted words are defined as follows:
carbonaceous chondrite: A major class of chondrites that mostly have Mg/Si ratios near the solar value and oxygen isotope compositions that plot below the terrestrial fractionation line.
type 2: Designates chondrites which are characterized by abundant hydrated minerals and abundant fine-grained matrix; chondrules are present; sulfides are Ni-bearing.
ungrouped: Describes meteorites which have been well-enough characterized to determine that they do not fit into any of the established groups.
Find all meteorites of type: C2-ung