Hematite after Magnetite (variety martite)

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

Specimen size: 9.2 × 6.6 × 7.3 cm = 3.62” × 2.60” × 2.87”
Main crystal size: 3.4 × 2.7 cm = 1.34” × 1.06”