Segmented with brass and aluminum. The wood is African Blackwood and Brown Mallee Burl. The dots are aluminum tubes with brass in the middle of the tube. The finial is African Blackwood with matching aluminum/brass dot. The aluminum segment has a thin sheet of brass sandwiched between the aluminum. The brass was quite thin and ends up being hard to see (see close up). This pen took a lot of time but was fun. Thanks for looking. Mike