rich with sulfates<\/a>, a kind of salt that contains sulfur and forms as water evaporates. But where past detections have been of sulfur-based minerals \u2014 in other words, a mix of sulfur and other materials \u2014 the rock Curiosity recently cracked open is made of elemental, or pure, sulfur. It isn\u2019t clear what relationship, if any, the elemental sulfur has to other sulfur-based minerals in the area.<\/p>\nWhile people associate sulfur with the odor from rotten eggs (the result of hydrogen sulfide gas), elemental sulfur is odorless. It forms in only a narrow range of conditions that scientists haven\u2019t associated with the history of this location. And Curiosity found a lot of it \u2014 an entire field of bright rocks that look similar to the one the rover crushed.<\/p>\n<\/div>\n<\/div>\n<\/div>\n