achondrite: a meteorite that is not a chondrite

aerolite: former name for a stony meteorite

anion (“ann-eye-un”): an atom or radical (group of atoms) that has an excess of one or more electrons and therefore has a negative electric charge

anomalous: describes a meteorite that has properties that are unusual for its classification

ataxite: an iron meteorite that does not display a Widmanstätten pattern when polished and etched

breccia: a stone that consists mostly of clasts

bronzite: a pyroxene with about twice as much magnesium as iron

calcium-aluminum-rich inclusion (CAI): a light-colored inclusion found in carbonaceous chondrites

caliche (“ka-lee-chee”): carbonate coating or adhesion to meteorites caused by soil and moisture on Earth

cation (“cat-eye-un”): an atom or radical (group of atoms) that has a deficit of one or more electrons and therefore has a positive electric charge

chondrite: an undifferentiated meteorite that has a composition similar to the non-volatile components of the Sun; most contain chondrules

chondrule: a spherical inclusion (round grain) formed from droplets of material that solidified in the early Solar System

classification: organization scheme; from most general to most specific: division, class, clan, group, subgroup

clast: a fragment of stone contained in a larger stone specimen

crusted: indicates that a specimen has a full or partial fusion crust; one or more layers of crust can partially ablate resulting in secondary and tertiary fusion crust

differentiated: describes a meteorite that originated from an asteroid that has undergone complete differentiation

differentiation: the process of separating heavier materials from lighter materials in an astronomical body due to internal heating

end slice: a slice where one side is the outside of the meteorite; sometimes called an endcut

enstatite: magnesium-rich pyroxene: MgSiO₃; also refers to a class of chondrites containing elevated percentages of enstatite

equilibrated: indicates that the original mineral components of a meteorite have been significantly altered (or blended) due to temperature and pressure

etched: a process where an iron or stony-iron meteorite has been polished and a weak acid applied to expose the Widmanstätten pattern

fall: one or more meteorites discovered as a result of a witnessed or documented impact event

fayalite: iron-rich olivine: Fe₂SiO₄

feldspathic: containing potassium-, sodium-, or calcium-aluminum silicates

ferrosilite: iron-rich pyroxene: FeSiO₃

find: one or more related meteorites discovered without benefit of a witnessed/documented impact event

forsterite: magnesium-rich olivine: Mg₂SiO₄

fragment: a broken-off piece of an individual

friable: describes a specimen that is prone to crumbling

full slice: a complete slice of an individual

fusion crust: full or partial coating on a meteorite due to frictional heating as it passes through Earth’s atmosphere

hammer: a fall that impacted a person, animal, or man-made object

hypersthene: a pyroxene with roughly equal amounts of magnesium and iron

impact sediment: sedimentary rock containing evidence of meteorite impact

impactite: rock created or modified by meteorite impact on Earth

individual: a complete meteorite

irons: meteorites that are all or nearly all metal

kakangariite: an extremely rare class/group of chondrites

kamacite: an alloy consisting of iron mixed with 5% to 12% nickel

lamellae: the bands or ribbons that comprise a Widmanstätten pattern

main mass: the significantly largest specimen of a named meteorite

mesosiderite: a stony-iron meteorite with a roughly equal mix of stone and metal

metachondrite: a chondrite that features obliterated chondrules due to temperature and pressure

meteor: a meteoroid that enters Earth’s atmosphere and glows due to frictional heating

meteorite: a meteoroid or piece of a meteoroid that survives its trip through the atmosphere

meteoriticist: a scientist who studies meteorites

meteoritics: the study of meteorites

meteoroid: a small solid solar system body

meteor-wrong: a terrestrial or man-made specimen that could be mistaken for a meteorite

monomict: the clasts in a breccia consist of the same kind of stone

olivine: a magnesium iron silicate: (Mg⁺², Fe⁺²)₂SiO₄

oriented: describes a crusted meteorite that did not tumble during flight, resulting in visible flow lines in its crust

paired: indicates that a named meteorite may be another specimen of a previously-named meteorite

pallasite: a stony-iron meteorite with olivine crystals embedded in a metal matrix

part slice: a part of a full slice

peridot: gem-quality olivine

plessite: a fine-grained mixture of kamacite and taenite

polymict: the clasts in a breccia consist of more than one type of stone

primitive achondrite: a meteorite originating from a body that has undergone partial differentiation

provisional: describes a meteorite that has been named and classified, but not officially approved by the Meteoritical Society

pyroxene: a chain magnesium iron silicate: (Mg⁺², Fe⁺²)SiO₃

regmaglypts: depressions on the exterior of a meteorite where more volatile areas have ablated away; sometimes called thumbprints

regolith: loose, fragmental material on a planetary or asteroidal surface

rumurutiite: a rare class/group of chondrites

ruster: a metallic specimen that is prone to oxidation

shale: describes an iron meteorite that has completely oxidized; the descriptor oxide is also used

shock: amount of stress applied to a specimen due to an impactor

siderite: former name for mixtures of iron and nickel that form the bulk of iron (and some stony-iron) meteorites

siderolite: former name for a stony-iron meteorite

silicate: any mineral consisting of tetrahedral anions containing silicon atoms bonded to four oxygen atoms

skeleton: a pallasite where the mineral component (olivine) has weathered away leaving the metal behind

specimen: an item of meteoritic (or meteorite-related) origin

stony: describes meteorites that are mostly comprised of stone or mineral (i.e. non-metal)

stony-iron: describes meteorites that have significant stone/mineral and metal components

strewn field: the area that encompasses a fall or find

taenite: an alloy consisting of iron mixed with 20% to 65% nickel

tektite: a specimen of glassy terrestrial debris from a meteorite impact

thin section: a very thin slice of a specimen that can be analyzed via its transmission of polarized light

total known weight (TKW): the sum of the weights of all specimens of a named meteorite

troilite: an iron sulfide (FeS) mineral more common in meteorites than on Earth

type specimen: the first meteorite found that represents a class or sub-class of meteorites

unclassified: a specimen that has not been submitted to a recognized meteorite testing facility

undifferentiated: a meteorite that originated from an asteroid that was not large enough to undergo differentiation

unequilibrated: indicates that the original mineral components of a meteorite have retained their structural integrity

ungrouped: describes a meteorite that does not belong to a current group or subgroup

weathering: deterioration or other changes to a meteorite due to environmental factors on Earth

Widmanstätten pattern: a distinctive pattern due to the coexistence of kamacite and taenite crystals in many iron meteorites; also known as Thomson structure

window: the portion of the interior of an individual that is visible after a small end-slice has been removed

xenolith: a specimen that contains two distinct types of stone

X-ray fluorescence (XRF): a technology that measures the elemental composition of a sample that can be helpful in meteorite identification