A volcanic tuff cone on the Hawaiian island of Oʻahu, known to Hawaiians as Lēʻahi.
Diamond Head is a volcanic tuff cone on the Hawaiian island of Oʻahu. Hawaiians know it as Lēʻahi, a name most likely derived from lae (promontory) and ʻahi (tuna), because the shape of the ridgeline resembles the dorsal fin of a tuna.
Its English name was given by British sailors in the 19th century, who named it after the calcite crystals on the nearby beach.