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 Howardite-an means:
"An achondrite from the howardite group, which has anomalous properties."
The highlighted words are defined as follows:
achondrite: A stony meteorite that lacks chondrules and originated on a differentiated parent body.
howardite: Howardites are an abundant group of polymict-breccia achondrites that appear to represent mixtures of eucrites + diogenites (these three linked groups are collectively known as HED meteorites and may come from asteroid 4 Vesta). The main minerals in howardites are pyroxene (largely orthopyroxene) and Na-poor plagioclase. A minority of howardites are rich in solar-wind noble gases and thus inferred to be regolith breccias. .
anomalous: Designates meteorites that have been determined to be a member of a specific group, but have certain properties that are unusual or distinctive.
Find all meteorites of type: Howardite-an