In Jessica Barnes’ palm is an ancient, coin-sized mosaic of glass, minerals and rocks as thick as a strand of wool fiber. It is a slice of Martian meteorite, known as Northwest Africa 7034 or Black Beauty, that was formed when a huge impact cemented together various pieces of Martian crust.
Source:
https://phys.org/news/2020-03-martian-mash-meteorites-story-mars.html