Green Sand Beach

 

Mahana Beach, near South Point.

Olivine Crystals in Lava Rock are the source of the green sand found on the green sand beach.

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Green Sand Beach

And He Walks With Me

Green Sand Beach

Green Sand Beach

Green Sand Beach

Green Sand Beach

Pololu Valley Kohala

Green Sand Beach

Double pink Hibiscus

Green Sand Beach

The invisible things of him from the creation of the world are clearly seen

Photographs by Abby,  Green Sand Beach

Papakōlea Beach (also known as Green Sand Beach or Mahana Beach) is a green sand beach located near South Point, in the Kaʻū district of the island of Hawaiʻi. One of only four green sand beaches in the world, the others being Talofofo Beach, Guam; Punta Cormorant on Floreana Island in the Galapagos Islands; and Hornindalsvatnet, Norway. It gets its distinctive coloring from olivine sand eroded out of the enclosing volcanic cone.

Papakōlea Beach is located in a bay half circled by Puʻu Mahana, a tuff ring formed over 49,000 years ago and associated with the southwest rift of Mauna Loa. Unlike cinder cones, tuff rings consist mostly of volcanic ash produced by violent interactions of magma with groundwater (Diamond Head, on the Island of Oahu, is another example of a tuff ring). Since its last eruption, the tuff ring has partially collapsed and been partially eroded by the ocean. The beach is sometimes named after the tuff ring, and sometimes after the area of land called Papakōlea, which comes from papa kōlea, which means plover flats in the Hawaiian language. Papakōlea is the area near the crater where Pacific golden plovers (Pluvialis fulva) are sometimes seen in winter

1020px Papakolea Beach   South Point Kona Big Island Hawaii

Wikipedia

The fragmental volcanic material (pyroclastics) of the tuff ring contain olivine, a silicate mineral containing iron and magnesium, also known as peridot when of gem quality. Olivine is a common mineral component of Hawaiian volcanics and one of the first crystals to form as magma cools. Olivine is locally known as “Hawaiian Diamond” and is notably found in Oʻahu’s famous Diamond Head landmark. The source of the green coloration of the beach sands is due to the olivine crystals (whose green color is due to ferrous iron) which are winnowed from the eroding headland by the action of the sea. Olivine, being denser than the ash fragments, glass and black pyroxene of the rest of the rocks and lava flows, tends to accumulate on the beach whereas the less dense volcanic sand is swept out to sea.

Olivine Crystals in Lava Rock. This is the source of the green sand found on the green sand beach

Although these crystals are eventually broken down by weathering and chemical action (olivine is decomposed by carbon dioxide and water, faster as grain size decreases) and washed away, the constant erosion of the cinder cone ensures a steady supply of sand for the foreseeable future—eventually, however, the supply will run out and the beach will look like any other.

Random shots from other locations on the Big Island. Contributed by Abby

 

 

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