Black Sand Beaches. Black sand at Kalapana. This new black sand beach is forming after the old one was swept away by a lava flow in 1986. The sand on all black sand beaches on Hawaii is made out of tiny fragments of lava. In contrast to the green and white sand, most of the black sand is created almost instantaneously. When hot lava enters the water it cools down so suddenly that it solidifies, and shatters into large amounts of black sand.