The Haverö meteorite

The meteorite Haverö, which fell on 2 August 1971 in Finland is a representative of a rare, but highly interesting group of stony meteorites-ureitites. Like other ureilites it is enriched in carbon (up to 2%) chiefly represented by diamond and graphite. The meteorite is strongly recrystallized; as a result its chief mineral component-olivine-has been transformed into a mosaic of small grains among which kamacite with an extremely low Ni content ( 1.7%) is distributed. Polysynthetic twinning is characteristic of pyroxene grains. The meteorite is penetrated by a system of cavities being stretched approximately in one direction. The cavities are sometimes occupied by kamacite plates containing 4% Ni. The peculiarities of the mineral and chemical composition of the meteorite indicate that its material had formed during a disequilibrium process. The content of cosmogenic isotopes witnesses to an unusual orbit of the meteorite.