Hematite after Magnetite (variety martite)

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

Specimen size: 9.7 × 7.7 × 5.7 cm = 3.82” × 3.03” × 2.24”
Main crystal size: 5 × 4.5 cm = 1.97” × 1.77”