Hawaii The sand of Hawaii's black beaches is obsidian - volcanic glass created by magma that flowed to the sea and then cooled rapidly.
(Hawaii; is; obsidian - volcanic glass created by magma that flowed to the sea and then cooled rapidly) (obsidian - volcanic glass created by magma; flowed; to the sea)
Hawaii obsidian - volcanic glass created by magma
is flowed
obsidian - volcanic glass created by magma that flowed to the sea and then cooled rapidly
to the sea