Darkwood
A wood near as hard as steel and as light as pine, grown in Eldamar
Not an object but a material: a wood that comes near steel for hardness and stays about as light as poplar, in some pieces as light as pine. Breaking a splinter off a length of it takes real effort, and the splinter that comes free is stiff enough to go through a glove and out the other side.
Koa met it first as a snapped axle on a merchant’s wagon, a wagon built of the stuff, which was itself a statement about the family that owned it. The word for it came back to him second-hand and badly pronounced, Ki laati, and he knew it the moment he heard it, though he could not say how it ought to sound. It grows in Eldamar, and Phillipa buys it off the Eldamar shipments through a town in Vala. It is said to hold magic. Nothing has yet shown that it does.
In Haudh-Gwenn it turns up older than the buildings around it. A councilman’s wine cellar held an off-sized rack of it hung on a Mól filigree catch, and behind the rack a stair; above, a Darkwood door that opened for nobody but Koa. Where it shows up in a foundation, the foundation is Mól, and older than the town standing on it.