Olivine Beach on Big Island of Hawaii
January 30, 2008
The Big Island of Hawaii is a great place to explore beach sands. Here one can admire black, white and even green sands. The island’s South Point is the southernmost spot in the United States. It is also home to the green sands of Papakolea beach on Mahana Bay. In Hawaiian Papakolea means "plover flats" which takes its name from the birds that live in the area. The green color of the sand is a result of olivine crystals that have been eroded from the magma of Puu Mahana (“warm hill”) volcanic cone. Wave action carries away most of the lighter particles created by erosion leaving the heavier olivine, which contains iron and magnesium, on the beach. Green sand beaches are rare. They are only found in areas on the periphery of a volcano combined with high wave action. Another green sand beach is on the island of Guam. A more out of this world place to find green sand, though most likely not on a beach, is inside a comet. In July of 2005 NASA scientists detected olivine crystals, somewhat smaller than the ones on the beach in Hawaii, inside the comet Tempel 1 during the Deep Impact mission.