A piece of ironwood seen from below

At a previous meeting, Martin Mueller showed off this piece of ironwood. Ironwood is not a rock or mineral, and although it may look similar, ironwood is not petrified wood. It is a name for many different types of wood that are said to be hard. It has a nice wood grain texture at the polished bottom. Sadly, I have forgotten what kind of wood this is and where it came from (it wasn’t from Westeros!). Does anybody know?

A piece of ironwood seen from the side.