Hematite after Magnetite (variety martite)

Payún Matru Volcano, Malargüe, Malargüe Department, Mendoza Province  Argentina (2008)

Specimen size: 9.7 × 3.8 × 3.5 cm = 3.82” × 1.50” × 1.38”
Main crystal size: 9.3 × 3.8 cm = 3.66” × 1.50”