Hematite after Magnetite (variety martite)

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

Specimen size: 7.4 × 6.3 × 4.7 cm = 2.91” × 2.48” × 1.85”
Main crystal size: 3.5 × 2.5 cm = 1.38” × 0.98”