There should be plenty of gold on Mars. There are lots of extinct river beds to dredge and there's no reason to believe there aren't going to be pockets of gold at the bottom. The only question is, can it be mined? Need lots of infrastructure and water for that. And is the cost of mining more than the gold you'll get? (Hint: Yeah, it's probably a net-loss operation) Maybe the adventure is reward enough. There are plenty of times I've gone out looking for gold and came up short. Question is, can Elon Musk scale up the gold fever? Oh, wait, <insert obligatory "space is fake and gay" remark>.