Macassar Ebony (Diospyrus celebica) is a striped ebony from New Guinea or islands of East Indonesia. Macassar ebony is a striking wood that is black with streaks of light golden brown. Though not technically accurate, I will refer to any striped ebony as Macassar (since I don't really know where my ebony comes from).
Some suppliers and luthiers characterize it as being similar to Brazilian rosewood, but I find it to be considerably heavier and less stiff. Ebony guitars tend to be strong bass performers making them especially good for rhythm guitars or twelve-strings.