Sapphire Pool (by bhophotos)
Sapphire Pool, named for its blue, crystal-clear water and for its resemblance to an Oriental sapphire, was once a placid hot pool, now at around 200º F. It was not until after the 1959 earthquake that major eruptions occurred. For several years following the earthquake powerful eruptions at two hour intervals reached 150 feet. The force of the eruptions caused the crater to double in size, destroying the biscuit-like formations around its edge, and the crystal-clear water became murky. By 1968 Sapphire ceased to function as a true geyser. Today Sapphire still retains its crystal-clear, blue water, and still violently boils and surges occasionally.