Hematite after Magnetite

specimen number:
2063009

location:
Payun Matru Volcano, Agua Escondida, Malargue, Mendoza, Argentina

description:
A loose floater sharp skeletal crystal grouping of what was once magnetite, this now replaced by lustrous sparkling micaceous micro hematite. Complete all around with no points of attachment, this is in great condition. From the very early 2000's. The specimen comes with a previous label from the collection of Ray DeMark.

The Payun Matru Volcano, located in the Malargue Department of Mendoza, Argentina, is a large shield volcano featuring a summit caldera that formed through major activity between 168,000 and 82,000 years ago. Its geological history spans from the Plio-Pleistocene period to recent times, characterized by extensive basaltic and trachytic lava flows, including some of the longest Quaternary lava flows on Earth. While it does not have traditional opening and closing dates like a human-made structure, volcanic activity has occurred intermittently over hundreds of thousands of years, with the most recent minor eruptions taking place around 500 years ago, leaving the volcano currently dormant.

This region is particularly famous for producing exceptional mineral pseudomorphs known as martite, which consist of hematite completely replacing original magnetite crystals. During this alteration process, the mineral changes its internal composition while perfectly preserving the sharp, silvery-grey octahedral geometry and skeletal hopper crystal forms of the original magnetite. These specimens often display brilliant metallic lusters and open windows across their crystal faces, making them highly prized among mineral collectors for their striking sculptural appearance.

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