Martit (hematite after magnetite) - Payun Volcano, Mendoza, Argentina
 
Strongly skeletonized hematite after magnetite. This variety, known as Martit, comes from a 2008 find at Payun Volcano in Argentina. The all-round crystallized crystal is very shiny and partly covered with a thin layer of shiny hematite crystals. Wonderfully aesthetic collector's item.