Hematite after Magnetite (variety martite)

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

Specimen size: 10.6 × 5.1 × 4 cm = 4.17” × 2.01” × 1.57”
Main crystal size: 3.5 × 2 cm = 1.38” × 0.79”