Widmanstätten Pattern

Widmanstätten Pattern as seen in the Glorieta Mountain pallasite. Image Credit: Mendy Ouzillou

Characteristic cross-hatched pattern visible on the surface of octahedrites, pallasites and even large metal blebs in chondrite melts and mesosiderite nodules after polishing and etching with an acid solution like nital (nitric acid in solution with ethanol). The acid will preferentially etch the iron based on its nickel content – Ni-rich taenite and Ni-poor kamacite. It is named after its discoverer, Austrian mineralogist Alois von Beckh WidmanstÃtten (1754-1849).