How do I read a meteorite label?
A typical label gives the official name, classification, fall or find date, location, mass and source. Codes such as L6, S3 or W2 describe type, shock and weathering.
Meteorite labels pack a lot of information into a small card. Here is how to read a typical one.
Name. The official name, such as 'Allende', 'Gao-Guenie' or 'NWA 869'. It should match the name listed by the Meteoritical Society.
Classification. This tells you the type: - A group letter or code, such as H, L, LL, CM, CV or EH for chondrites; names such as eucrite, howardite or shergottite for achondrites; or groups such as IIIAB for irons. - A petrologic type, such as 3, 4, 5 or 6 for chondrites. Type 3 is least heated; type 6 is most heated. Types 1 and 2 indicate water alteration. So L6 is a heated L chondrite, and CM2 is a water-altered CM chondrite. - For irons, a structural class may be given, such as 'medium octahedrite'.
Shock and weathering. Some labels include shock stage, such as S1 to S6, and weathering grade, such as W0 to W6. An L6 S4 W2 has been moderately shocked and moderately weathered.
Fall or find. Whether it was seen to fall, and the date or year of fall or find.
Location. Country and region.
Mass. The weight of your specimen, and sometimes the total known weight of the meteorite.
Specimen type. Slice, end cut, individual, fragment or crusted piece.
Source. The dealer, collector or institution that supplied it, and sometimes a catalogue number.
Check the name against the official list and keep the label with the specimen.