GRA98033 a brecciated eucrite about 5 cm across, found in the Graves Nunataks region of Antarctica.
Eucrites are achondritic stony meteorites, many of which originate from the surface of the asteroid4 Vesta and are part of the HED meteorite clan. They are the most common achondrite group with over 100 meteorites found.
Based on differences of chemical composition and features of the component crystals, they are subdivided into several groups:[2]
Non-cumulate eucrites are the most common variety and can be subdivided further:
Main series eucrites formed near the surface and are mostly regolithbrecciaslithified under the pressure of overlying newer deposits.
Stannern trend eucrites are a rare variety.
Nuevo Laredo trend eucrites are thought to come from deeper layers of 4 Vesta's crust, and are a transition group towards the cumulate eucrites.
Cumulate eucrites are rare types with oriented crystals, thought to have solidified in magma chambers deep within 4 Vesta's crust.
Polymict eucrites are regolithbreccias consisting of mostly eucrite fragments and less than one part in ten of diogenite. They are less common.
Etymology
Eucrites get their name from the Greek word eukritos meaning "easily distinguished". This refers to the silicate minerals in them, which can be easily distinguished because of their relatively large grain size.
^Mittlefehldt, McCoy, Goodrich and Kracher: Non-chondritic Meteorites from Asteroidal Bodies, In: Reviews in Mineralogy Vol. 36, Planetary Materials, Mineralogical Society of America, 1998.
^Sutherland, D. S. (1982) Igneous Rocks of the British Isles, Chichester, John Wiley, page 536.
