African Blackwood or Mpingo
Excerpt from Ebenhart's Website by Ebenhart Botha:
African Blackwood/Mpingo (Dalbergia melanoxylon) is an almost pitch black wood with a bright yellow outer layer, and has the highest density of all woods. This makes it extremely hard and durable, but also quite tricky to work with.
When a Briar pipe is smoked constantly, it becomes cloggy very quickly, and a foul taste appears shortly after lighting. This is not the case with Dalbergia for it is too hard and dense for that. A decently designed oil chamber takes care of that, and with the added help of a filtering system, a dry smoke is a certainty.
This wood will outlast Briar with at least three times the lifespan. It is however a rare and expensive wood, for a solid piece to make a pipe out of is rare.