Hematite after Magnetite (variety martite)

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

Specimen size: 7.3 × 5.4 × 4.3 cm = 2.87” × 2.13” × 1.69”
Main crystal size: 3.2 × 3.2 cm = 1.26” × 1.26”