... Mars . ... Precious metals . ... Some of the world's rarest and most precious metals, including platinum and iridium, could owe their presence in Earth's crust to iron and stony-iron meteorites, fragments of a large number of asteroids that underwent significant geological processing in the early solar system. ... abundance ratios of HSE in Earth's crust are much higher than those found in stony meteorites, known as chondrites, which represent the pristine material from the early solar system. ...