Koa (Acacia koa) is a tropical hardwood that is native to the Hawaiian Islands and the only place it grows in quantity

            The thin, light-colored sapwood encompasses the heartwood that is generally reddish brown to dark brown with dark grain and may have wavy or curly golden reflections with some tones of gold, black or even dark purple. The Koa wood tends to take on a three-dimensional iridescence quality (or "Tiger-eye" effect) when rubbed with oil, or given a high glossy polish. (More on Koa . )