Karite – diamond fossil: A new type of natural diamond

Impact diamond is one of perspective natural type of superhard carbon materials, forming huge resources sometimes, such as Popigai impact structure counting the largest diamond storage on the Earth. By present, there are two known types of impact diamonds – after-graphitic and after-coal varieties formed from different carbon precursors. Here we present for the first time a new impact diamond type – diamond fossils, named by “karite”, formed about 70 Ma from unmetamorphosed organics in the giant Kara impact crater (Pay-Khoy, Russia). A full complex of the diamond fossil characteristics is described proving its nature and phase state. Karite is presented with supernanocrystalline diamond aggregates, nicely preserves tiny cell morphology and relict features of lignin and cellulose. The diamond fossils are spread widely through the Kara impactites, point to possible wider distribution of impact diamonds within large impact occurrences around the world, can be used for impact modeling, astrobiological and material studies.