Hawaiite is an olivine basalt with a composition between alkali basalt and mugearite.[1] It was first used as a name for some lavas found on the island of Hawaii.
It occurs during the later stages of volcanic activity on oceanic islands such as Hawaii,[2] which happens to be when the alkali metals are most present.[3]
In gemology, hawaiite is a colloquial term for Hawaii-originated peridot, which is a gem-quality form of the mineral olivine.[4]