sand - sand with grains derived from olivine weathered from basalt and coral from an offshore reef - 250 ml glass display bottle with ground-glass stopper

Olivine forms at temperatures and pressures found in the earth's mantle and is carried up in the basalt from a mantle hot spot that forms the Hawaiian Islands.  Beaches are uncommon on the seacliff-ringed Island of Hawaii. Occasional small coves have sand derived primarily from basalt unless there is a coral reef offshore. Sand is derived from whatever material is locally available. This sand was collected in the 1994 from a tiny cove near South Point, Hawaii, where a local concentration of olivine had weathered out of the basalt and was concentrated by the waves. An offshore reef contributed grains of coral, which make up roughly half of this sand. Olivine is almost twice as dense as quartz, which is the typical source material of the white sand beaches of the continental USA, so it is not as easily swept out to sea by wave action.   Hawaii's white sand beaches at Waikiki were initially an import, from California. In the 1920s and 1930s sand was barged from Long Beach, though the impo