There are a lot of wonderful descriptions and terms associated with meteorites, impactites, and tektites, and becoming familiar with them will deepen your understanding of these treasures of our solar system:

Achondrite
Achondrites are stone meteorites which lack chondrules or metal flakes, but are rich in silicates; considered to be quite rare.

Ablation
Ablation is the process that removes material by heat and vaporization as a meteorite passes through the atmosphere.

Amino Acids
Amino acids are molecular units that make up proteins (proteins compose the majority of cellular structure, and act as enzymes for catalyzing cellular reactions). Amino Acids have been found in some very rare meteorites.

Asteroid
Asteroids are rocky leftover material from the formation of the Solar System which never became part of a planet or major satellite. Most meteorites are pieces of asteroids.

Ataxite
Ataxites , one of the types of iron meteorites also called silicated irons , contain Iron and a significant percentage of nickel (greater than 16%), forming a unique nickel-iron alloy. Ataxites do not exhibit Neumann lines or a Widmanstätten pattern when cut, polished, and etched with nitric acid or ferric chloride.

Basalt
Generally speaking, Basalt is a hard, black igneous volcanic rock with less than approximately 52% silica (SiO 2 ) composed principally of pyroxene and plagioclase. Since basalt has low silica content, it has a low resistance to flow, called viscosity. Extremely rare meteorites, like lunar basaltic meteorites, are basalts.

Bolide
Very bright meteors, called fireballs, which appear to break up or produce sound, are called bolides , from the Greek word bolis meaning missile.

Breccia
Breccia are rocks consisting of broken, angular fragments of rock (clasts) cemented together by a fine-grained matrix. Formed from regolith (loose, heterogeneous fragmental material covering solid surface material) during subsequent impacts.

Carbon
Carbon , atomic number 6 with the atomic symbol C, is a nonmetallic element distributed widely in nature in three forms: amorphous, graphite, and diamond. Carbon is found in abundance in the Sun, stars, comets, and atmospheres of many of the planets.

Chondrite
Chondrites are a relatively abundant type of stone meteorite, so named because they contain chondrules made up of minerals such as olivine and pyroxene. .

Chondrules
Chondrules are millimeter-sized spherical crystals of minerals such as olivine and pyroxene, imbedded in the stony meteorite matrix. The term comes from the Greek, chondros , meaning a grain of seed.

Cobalt
Cobalt, atomic number27 with the atomic symbol Co, is a metallic element characterized with a grayish tinge. Cobalt can be found in minute quantities in meteorites.

Comet
Comets, often referred to as snowy dirtballs, are composed of ices, which include carbon dioxide (CO2) and water ices, ammonia, organics, and sand like substances, as well as ions in the gas tail. It is believed that some extremely rare types of meteorites are actually cometary in origin.

Crater
Craters in meteoritics refer to impact-caused structures (one can also refer to volcanic craters). Craters can vary from microscopic to hundreds of miles across; our Solar System is littered with these impact features.

Crust
The crust is the surface of a parent body; part of the three major areas of the crust, mantle, and core. The geology and make-up of each of the areas is generally quite different, with the crust being composed of more silicated material.

Diamond
Diamonds within meteorites are formed in one of two ways. The first is due to collisions between asteroids. These collisions can be so violent and produce such high shock pressures that carbon is converted to diamond. The second type of meteoritic diamond is believed to have formed via a supernovae event. Both types are small; supernovae meteoritic diamonds are very small.

Differentiated
Differentiated in planetary composition terms generally refers to the process in which a parent body such as a rock planet or asteroid has separated into regions of different composition and density, such as the core, mantle and crust. Differentiation is not a well-understood process.

Enstatite
Enstatite, or E Chondrites, contains the silicate enstatite, an iron-free pyroxene. Two subclasses (H and L) of Enstatite Chondrites are dependant on iron content. Enstatite Chondrites are considered to be quite rare.

Eucrite
Eucrites, the most abundant of the Achondrites, are calcium-rich basaltic meteorites, meaning they are like volcanic rocks made primarily from basaltic plagioclase and pyroxene. Eucrites are nevertheless chemically different from terrestrial basalts and appear to be from the asteroid Vesta.

Falls
Falls in the field of meteoritics refers to the recovery of a meteorite or meteorites when a bright fireball is seen and meteorite(s) are recovered from the fall or meteorites are recovered just after they fall. (See Finds)

Feldspar
Feldspar is the name of a group of rock-forming minerals which make up around 60% of the Earth's crust. Feldspars are aluminum silicate minerals with varying amounts of sodium, calcium, and potassium.

Finds
Finds are meteorites that are not seen to fall, but are simply discovered then recovered some time after they fell. Most meteorites recovered are found as finds; there is a ratio of about 1 fall for every two finds that are made. ( See Falls )

Fireball
Fireballs are very bright and characteristically-slow moving meteors, loosely classified as such if it is brighter than the planet Venus

Fusion Crust
The fusion crust is an unusually dark, thin melted surface layer, due to the melting of minerals on a meteorite's surface during the plunge through the Earth's atmosphere.

Graphite
Graphite , a form of the element carbon, is found in some iron, ordinary Chondrite and carbonaceous chondrites meteorites. Graphite, often as nodules, is black and quite soft. Graphite nodules, one of the three forms of carbon found within meteorites, can ablate from the meteorite as it passes through the atmosphere or through weathering.

Hexahedrite
Hexahedrites , one of the types of Iron meteorites, contain iron, between 4.5 and 6.5 percent nickel, and large crystals of kamacite, an iron-nickel crystal containing up to 7.5 percent nickel. Hexahedrites are named for its cubic (hexahedral) crystal structure. When cut, polished and etched with nitric acid or ferric chloride, Hexahedrites produce a series of lines called the Neumann lines.

Igneous
Igneous , from the Latin term ignis , meaning "fire," refers to rocks which are formed when molten rock cools and solidifies. There are a number of rare meteorites – in particular some of the lunar and Martian meteorites – which are igneous in nature.

Impact
Impact is the term used when a meteorite, asteroid, or comet strikes a body. The associated term impactor can also be used to describe the meteorite, asteroid, or comet.

Impactite
Impactites are impact-caused fused silica-based material. These are often the only evidence in addition to a crater of very old celestial impacts and were first discovered in 1932 around the Australian Henbury craters. This slag-like glassy material is rock melt due to the high heat and pressure of the meteoritic impact.

Inclusion
An inclusion refers to a body of foreign material enclosed within the primary matrix of a meteorite.

Iridium
Iridium, atomic number 77 with the atomic symbol Ir, is a metallic element. Iridium was found in significant quantities in rock layers separating the K-T Boundary, the Cretaceous from the Tertiary Period. It is theorized that the Iridium layer was deposited due to an asteroid or comet impact in the Yucatan Peninsula , ending the reign of the dinosaurs and ushering in mammals.

Iron
Iron, atomic number 26 with the atomic symbol Fe, is a metallic element. Iron is found as the primary component in Iron meteorites and is also found in all Stony-Irons and most Stony meteorites.

Isotope
Isotopes are elements with the same number of protons, thus same atomic number, but different numbers of neutrons. For example, Hydrogen has three isotopes: Protium with no neutrons, Deuterium with one neutron, and Tritium with two neutrons.

Kamacite
Kamacite is a metal alloy composed of iron and nickel with not more than 7.5 percent nickel. This is an important Iron meteorite alloy.

Lunar
Lunar is a phrase meteoriticists and meteorite collectors use when referring to Lunar Meteorites. These rare meteorites have been found in very small numbers and are impact breccias. They are believed to have been blasted off the Moon as ejecta from high-velocity impact events.

Main Mass
The Main Mass refers to the total pre-atmospheric mass of a meteoroid or the largest known fragment of a meteorite.

Mantle
The mantle is a zone or region in a differentiated parent body between the crust and the core.

Martian
Martian , like Lunar, is a phrase meteoriticists and meteorite collectors use when referring to Martian Meteorites. These rare meteorites are found in small numbers and are divided into four groups. They are also believed to have been blasted off Mars as ejecta from high-velocity impact events.

Matrix
The Matrix in meteoritics refers to the fine primary material in a meteorite that surrounds other materials such as inclusions, chondrules and clasts in breccia.

Meteor
Meteors are the momentary steaks of light that last about a half a second on the average produced by a meteoroid as it is ionized (or heated) to incandescence in the atmosphere. Few of these objects survive their encounter with our atmosphere.

Meteorite
Meteorites are generally larger material that survive their encounter with an atmosphere and impact a body's surface. Since there is no lunar atmosphere, meteoroids strike the surface as meteorites (no meteor visible). Not only have meteorites been recovered on Earth, but one has been imaged on the surface of Mars. And the Solar System is littered with evidence of impacts.

Meteor Showers
Meteor Showers occur when Earth passes through cometary dust left behind as a comet orbits the Sun. This dust burns up in the Earth's atmosphere and does not make it to the ground as a meteorite. One meteor shower – the Geminids which peak in December – might be associated with an asteroid rather than a comet.

Meteorite Showers
Meteorite Showers – not to be confused with meteor showers – occur when a group of meteoroids enters the Earth's atmosphere, impacting Earth as a group or due a meteorite breaking up into multiple fragments with these fragments impacting Earth.

Meteoritic
Meteoritic refers to an object that is meteorite-related.

Meteoriticist
A Meteoriticist is a scientist who studies meteorites and associated fields, such as craters.

Meteoroid
Meteoroids are material in space not associated with comets. Meteoroids can be made up of various types of materials, often materials from the formation of the Solar System. Meteoroids are smaller than asteroids.

Moh's Scale
The Mohs' Scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. It was created by Friedrich Mohs, a German mineralogist in 1812, to define hardness in minerals. Mohs based the scale on ten minerals with the hardest one being diamond. The hardness of a mineral is measured against the scale by finding the hardest material that that the given mineral can scratch, and/or the softest mineral that can scratch the given mineral.

Nebula
Nebulae represent a number of different types of objects: clouds of dust and gas. The word nebula has had various meanings, but in its original Latin, it meant cloud. Before the invention of the telescope, nebula was used to denote extended objects versus the points of light (stars). After the invention of the telescope, other deep sky objects—including galaxies—were referred to as nebulae. Today, nebula refers only to interstellar clouds of dust and gas, not clusters of stars or external galaxies.

Nickel
Nickel, atomic number 28 with the atomic symbol Ni, is a metallic element. Nickel is found as a component in Iron meteorites and is also found in all Stony-Irons and most Stony meteorites. The qualitative testing for nickel is one way to verify a specimen as a candidate meteorite or meteorwrong.

Nodules
Nodules of graphite are found in a number of meteorites. These nodules are usually egg-shaped inclusions and are often referred to as “primary structures” in iron meteorites. Most of these nodules have rims of taenite and schrebesite that has been precipitated on the nodules during the cooling and crystallization phase. The surrounding taenite is highly resistant to Earth processes which eat away at the meteorite.

Octahedrite
Octahedrites, one type of Iron meteorites, contain iron and between 6.5 and 12.7 percent nickel. Octahedrites can also contain chromite, cohenite, diamonds, and schrebesite, along with nodules of graphite and troilite, which are often surrounded by kamacite. Octahedrites are named for its octagonal, or eight-sided, crystal structure. Octahedrites produce a wonderful crystalline pattern of lines after being cut, polished, and etched with nitric acid or ferric chloride, called the Widmanstätten Pattern .

Olivine
Olivine is a silicate of either magnesium (Mg) or iron (Fe) or both in varying amounts. Olivine is common in both stone and stony-iron meteorites. A common gem name for olivine is Peridot.

Olivine-Bronzite
Olivine-Bronzite is the name given to the H class of Ordinary Chondrites as this class is composed of olivine and bronzite, a pyroxene with about 20% FeSiO 3 .

Olivine-Hypersthene
Olivine-Hypersthene is the name given to the L class of Ordinary Chondrites as this class is composed of olivine and hypersthene, a pyroxene containing 22-30% FeSiO 3 .

Parent Body
Parent Body is a term used in meteoritics to refer to the source of an impactor. For example the parent body of Martian meteorites is Mars. Most meteorite parent bodies are the asteroids.

Peridot
Peridot is the gem quality variety of forsterite olivine. It is bright yellow-green in color, and has a hardness of 6.5 on the Mohs scale.

Plagioclase
Plagioclase is a common rock-forming a series of feldspar minerals. Plagioclase consists of mixtures of these feldspars in solids with sodium and calcium ions.

Plessite
Plessite is a mineral composed of a fine-grained mixture of kamacite and taenite that fills in the space between the Widmanstätten Pattern in iron Octahedrite meteorites.

Plutonic
Plutonic is a term occasionally used when referring to the class of Stony Achondrite Dioginite meteorites. These rare meteorites are almost all orthopyroxene; large crystals of iron-rich hypersthene and bronzite with approximately 12 percent iron by weight.

Polycrystalline
Polycrystalline is material consisting of multiple small crystals. For example these crystals can be silicates or graphite.

Pyroxene
Pyroxenes are important silicate materials found in all stone meteorites. Various pyroxenes form by solid solutions with magnesium, iron, and calcium.

Recrystallization
Recrystallization occurs when a solid is dissolved in a minimal amount of boiling solvent and then cooled to form crystals without impurities.

Regmaglypts
Regmaglypts , also called “thumbprinting,” are depressions and cavities on the exterior of a meteorite produced by the process of ablating (melting) certain meteoritic minerals as the meteorite goes through the atmosphere.

Regolith
Regolith is a layer of loose, heterogeneous material covering solid rock on a celestial body. Regolith is found on the Earth, the Moon, some asteroids and some other planets. Lunar regolith is composed partially of rock and mineral fragments that were broken apart from underlying bedrock by meteoritic impacts.

<Selenium
Selenium , atomic number 34 with the atomic symbol Se, is a nonmetallic element which exhibits a grey, metal-like luster.

Serpentine
Serpentine is a hydrous magnesium silicate mineral with the chemical formula Mg 6 Si 4 O 10 (OH) 8 . Serpentine is commonly found in stony carbonaceous chondrites.

Silicates
Silicates represent a large group of minerals that contain silicon, oxygen (SiO 4 ) and one or more metals like magnesium or iron.

Strewn Field
The strewn field is a usually elliptical field defining a multiple meteorites fall pattern or path.

Taenite
Taenite is metal composed of a nickel-iron alloy with a nickel content varying from about 27% to 65%. Taenite is commonly found in Iron meteorites.

Tektite
Tektites are fused glassy material classified as dry – that is, they contain little water, are silica-rich, and somewhat similar in composition to volcanic glasses. Their exact origins are still debated, however the best explanation is that tektites are formed when an Impactor strikes the Earth with such force that surround terrestrial rock is vaporized and ejected into space. There the ejecta cools and re-enters Earth's atmosphere where it develops shape characteristics.

Troilite
Troilite is a bronze or brass colored magnetic sulfide of iron ( FeS ) common to many types of meteorites.

Volcanic
Volcanic rock is igneous rock that forms from the cooling of magma on the surface of a planet or asteroid.

Widmanstätten Pattern
Widmanstätten Pattern or figure ( Thomson Pattern ) is produced by broad kamacite bands sandwiched between narrow taenite bands, which are parallel to the octahedron's face found in iron-nickel Octahedrites. The Widmanstätten Pattern becomes visible after cutting, polishing, and then etching a sample Octahedrite in nitric acid or ferric chloride. The Widmanstätten Pattern is named after Alois Widmanstätten who supposedly was the first in 1808 to discover this Octahedrite pattern. However in 1804 William Thomson first noted the pattern, yet Widmanstätten is given credit .