This is one of the questions in the mineral trivia contest! It's actually the one that more people are getting wrong than any others. So i'll make an exception here and answer this question, so if you stumble upon this question think of it as a bonus answer.
The answer is halite. The lowest point on the earth is the Dead Sea (Israel and Jordan). The Dead Sea is a salt lake with a heavy saline concentration and mounds of evaporite halite forming throughout its shoreline.