Hematite after Magnetite (variety martite)

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

Specimen size: 11.4 × 8.7 × 4.6 cm = 4.49” × 3.43” × 1.81”
Main crystal size: 4.5 × 3 cm = 1.77” × 1.18”