Basaltic eucrite
A basaltic eucrite is a lava rock from Vesta's crust, made of pigeonite and calcium-rich plagioclase.
A basaltic eucrite is a fine- to medium-grained rock made mainly of pigeonite pyroxene and calcium-rich plagioclase, like a terrestrial basalt but drier and poorer in sodium. Most eucrites belong to this type. They formed as lava flows or shallow intrusions in the crust of the asteroid Vesta, about 4.5 billion years ago.
Many basaltic eucrites were later reheated, perhaps by being buried under newer lava, which caused exsolution in their pyroxenes and recrystallised their textures. Most are also breccias, broken and reassembled by impacts. They are often subdivided into main group, Stannern trend and Nuevo Laredo trend by their chemistry.
A cut basaltic eucrite looks speckled grey and white, with a shiny black fusion crust that is often glossy because the rock is rich in calcium and aluminium. Famous examples include Juvinas, Stannern and Millbillillie, which fell in Western Australia in 1960.
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