Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

I wish to knw if there is a material in the world of DnD FR is a material call Heartwood and what dose it do i know in BG 2 game there is a ring call Heartwood ring

Scanning this Tube wilt and this Viper tree article, I think it's the heart of a treant or other living tree.

In trees, the heartwood (duramen) is the dead, denser wood towards the core of the tree where sap doesn't flow, but where the majority of the tree's structure comes from. Conversely, the sapwood (alburnum) surrounds the heartwood, and is the living part of the tree where nutrients flow between the roots and leaves. All wood starts out as sapwood, but over time the inner portions which are not needed to pass sap change to heartwood to provide further reinforcement.

For example, the classic yew longbow was cut so that the natural divide between heartwood and sapwood would pass down the length of the bow stave. The heartwood was used in the belly of the bow, since it resists compression, while the sapwood was used on the back, since it is more stretchy. That way, you get a 'composite' effect from a single span of wood.

Don't think it has anything to do with any magical material.

There many material woods one is duskwood and then we have Zalantar(Darkwood,Blackwood)

Duskwood and Zalantar are different types of tree wood, much like ash, yew, oak, and pine would likewise have different properties. Heartwood and sapwood are different regions within the same tree - like I mentioned with yew, there is yew heartwood and yew sapwood which play different roles in the carving of a longbow.

look here http://nwn2.wikia.com/wiki/Material there is something call Ironwood material was use in nwn one