Ironwood

Well, other than being lighter than metal weapons, and holding an edge better than metal weapons, and not attracting rust monsters, and enhancing both runic and enchantment magics, Ironwood makes some of the most flavorful smoked meats in the world... if you can get it hot enough to smolder.

— Jasper Cameron, Leader of the Bronze Ravens.

Okay, look, yes, it is one of the rarer woods in the world. Yes, you have to cross thousands of miles of murder desert or traverse the most dangerous mountains in the world to have even the chance of getting some. And processing it takes a master elven wood-singer, a Druid elder, or the specific techniques of the dwarf clan that you are racing to get a fallen branch or leaf. The reward, though.... have you heard of Gungnir (yes, contrary to popular belief, it was not made from the wood of Yggdrasil) or perhaps Fragarach or Destiny's Needle. Not to mention the numerous famous mages staves and the legendary Armor of the Frozen Ancestors.

Properties

The documented properties of wood from Jarvnidartre are more akin to metal than wood. However it is worked the same as any other wood.... sort of. I mean, you need tools of the highest quality or a particular level of magic, but once you get over that hurdle you are good to go.

Fire Resistance

The fact the it is wood from a miles tall world tree called the Iron Tree should probably clue you in that Ironwood is much more fire resistant than a typical wood. It is possibly to get it hot enough to smoulder if you have access to a Ghostwalker forge or know a particularly charitable and appropriately ancient red dragon... although if a demon or devil from certain abyssal plains ows you a favor, that could also probably work too. Needless to say the wood is nearly fireproof.
But if you DO have access to one of the above mentioned methods, you can fire-harden the wood. The near weightless quality of mythril combined with the hardness of adamantine and the beauty of a damascus pattern. The sheen that it takes on, more beautiful than a stained glass cathedral. Enhance this beauty with magical runes and you have a peerless artifact that will endure long after you are gone.

Magical Capacity

It is often noted that anything made from wood from one of the World Trees has more magical capacity than anything outside of ancient dragon bones or perhaps the horns of an arch-devil. Most materials would fall prey to the spell if you tried to make a want od desintegration, but Ironwood will take the spell in easily. It alsmost seems to thirst for magic. Ironwood shields carried by the Ghostwalker Dwarves appear to almost drink in most offensive magics. The ability of an Archwizards staff to ground out lightning bolts and other spells is also due to this property.
There is a rumor that a drago-lich has even managed to make its phylactery out of Ironwood, but given what Ghostwalkers do to undead denizens found in the Sapphire Sands this seems unlikely.

Cooking Fuel

Yes, you read that correctly. The shavings of worked Ironwood are often used by the Ghostwalkers in making smoked meats that taste just divine. In addition, when burned in this way, stories of lost ages play out in the smoke that is given off. It is thought that it is from these smoke-stories are thought to have provided the dwarves with the secrets of planeshifting. Also, the smoked meat of a desert tortoise is said to be how they brokered their treaty with the bronze dragons of the area.

Type

Wood