This hematite is from the Payun Matru volcano in Altiplano de Payun Matru, Marargue Department, Mendoza, Argentina. This area, which is a national park, contains eight different minerals including these hematites that were formed by volcanic fumarole action. This specimen is a floater cluster of octahedral, twinned and hoppered crystals of magnetite that have been replaced with specular hematite crystals. The replacements are sharp and well defined. They have a steel-grey color and sparkling metallic luster. It measures 1 1/16 x 1 x 5/8 inches or 26 x 25 x 16 mm.