Marcasite And Chalcedony On Matrix From Indiana- Collectors Piece, Home DécorMarcasite And Chalcedony On Matrix From Indiana Collectors Piece, Home Dcor Weight 1. 160kg Size 13cm by 13cm Thickness 11cm Marcasite is an Iron oxide that has the exact same chemical makeup of Pyrite, but forms in a completely different crystal structure. Unlike Pyrite, Marcasite does not exhibit a cubic identity, instead, it crystallizes in a variety of other forms, such as tabular, pyramidal, nodules, fibres, flakes, and masses. Marcasite has