Compositional control of color in halites from Searles Lake, California

Event Center A & B

Halite collected from muds of Searles Lake is commonly pink to red, making it a coveted specimen for rock and mineral collectors. Similar pink halite from the Salt Range in Pakistan, often sold as Himalayan Pink Salt, is prized for its purported natural affinity. Chemical analysis of Searles pink halite shows that the halite is rich in pink to reddish carotenoids. X-ray element analysis shows that iron oxides, which are commonly geological reddening agents, are not the source of the color. However, halophilic bacteria are well known producers of carotenoids. Halophilic bacteria are the major reason why water bodies in which they live a pink to red color, e.g. The Red Sea, The Great Salt Lake and Owens Lake. They can tolerate extreme habitats, i.e. they are extremophiles, and survive in hypo- to hyper-saline aquatic systems. Initial spectrophotometric analysis indicates that absorbance levels and fluorescence tentatively correlate fluctuating preservation and/or bio-productivity of halite-rich environments.