sixpenceee:Black sand beaches occur where lava flows enter the sea. The sand is quenched lava that i
sixpenceee:Black sand beaches occur where lava flows enter the sea. The sand is quenched lava that is mostly glass. The finely divided glass and crystals weather quickly so the beaches don’t usually last for long periods. They are located in various parts of the world such as Hawaii, Iceland and Alaska. -- source link