Iron, IID

IID Iron meteorites are a rare and distinct group within Iron meteorite classification, representing material from the metallic cores of differentiated asteroids. Formed over 4.5 billion years ago, they crystallised from molten iron-nickel metal as their parent bodies cooled over extended periods. The ‘IID’ designation reflects their specific nickel content and trace element composition, which separates them from other Iron groups and indicates a unique formation history.

IID Irons are composed primarily of iron-nickel metal and can display Widmanstätten patterns when cut and etched, although these patterns may vary in scale depending on composition and cooling rate. Their structure reflects slow crystallisation within a parent body, producing interlocking metallic crystals that record the thermal history of the core. Compared to more common Iron groups, IID meteorites are less frequently encountered, and their appearance can range from relatively uniform to more structured depending on the specimen.

Studying IID Iron meteorites provides valuable insight into the diversity of asteroid core formation and cooling processes. Their distinct chemical signature helps refine classification systems and improves understanding of how different parent bodies evolved in the early solar system. For collectors, IID Irons are highly desirable due to their rarity and defined classification. Each specimen represents an uncommon example of ancient metallic core material, offering both scientific significance and collectability.