IID irons
IID irons are a magmatic group of medium to fine octahedrites rich in gallium and germanium.
IID irons are a magmatic group of iron meteorites with about twenty members. They are medium to fine octahedrites with roughly 10 to 11 per cent nickel and are noticeably rich in gallium and germanium, as well as in phosphorus, so schreibersite is common.
Their trace element trends follow the pattern of fractional crystallisation in a single core. Studies of their isotopes place them among the carbonaceous-type, or CC, iron groups, meaning their parent body probably formed in the outer Solar System beyond Jupiter's early orbit, then was scattered inwards.
The Carbo meteorite from Sonora, Mexico, is a well-studied IID iron. Members of the group often show abundant large schreibersite crystals with swathing kamacite on etched slices. Grouping meteorites like these by chemistry and isotopes lets scientists count and map the asteroid cores that once existed, adding to the story of how the Solar System's building blocks were shuffled.
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