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 Chondrite-ung means:
"An ungrouped chondrite that has not or can not be assigned to one of the major classes like carbonaceous chondrites or ordinary chondrites."
The highlighted words are defined as follows:
ungrouped: Describes meteorites which have been well-enough characterized to determine that they do not fit into any of the established groups.
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.
ordinary chondrite: A major class of chondrites, distinguished by sub-solar Mg/Si and refractory/Si ratios, oxygen isotope compositions that plot above the terrestrial fractionation line, and a large volume percentage of chondrules, with only 10-15 vol% fine-grained matrix.
Find all meteorites of type: Chondrite-ung