Barringerin

Barringerin is a naturally occurring sulfide mineral first identified in the late 20th century within the geologically significant Barringer Crater in Arizona. It is classified in the pyrrhotite group and is chemically composed of iron, sulfur, and trace amounts of nickel and cobalt, giving it the approximate empirical formula Fe_3.5S_4. The mineral was named after the Barringer Crater Research Institute, where its discovery was first reported.

The mineral was discovered during a systematic survey of the crater's ejecta blankets, which revealed small, lamellar crystals that were initially mistaken for pentlandite. Subsequent X-ray diffraction and electron microprobe analysis confirmed the unique crystal structure of Barringerin, characterized by a close-packed arrangement of iron sulfide octahedra with interstitial metal ions. The crystals are typically microcrystalline with a pale gray to greenish hue and exhibit a metallic luster.

Barringerin occurs predominantly as a secondary mineral in highly oxidized hydrothermal vein systems and is typically associated with pyrite, greigite, and other nickel-iron sulfides. Its presence has been linked to the high-temperature shock metamorphism processes associated with the meteorite impact event that formed the crater.

Although Barringerin has limited industrial applications due to its scarcity, it is of significant academic interest. It serves as an indicator mineral for the study of impact-related hydrothermal alteration and the redistribution of nickel and cobalt in post-impact environments. Researchers also use it as a natural proxy for understanding metal transport mechanisms in sulfidic ore deposits.