rooks and minerals

mayfieldgroup:

A geological oddity - Lake Retba, or as the French call it, Lac Rose. 


Not really geological so much as biological. Lake Retba is hypersaline, which makes it a perfect place for Dunaliella salina, a salt-loving (halophilic) microalgae to live, which is what gives it that pink colour. (Dunaliella is also often used in dietary supplements and cosmetics.)