From Lost Fables Wiki
Acorns of the world tree are, by far, the most common piece of it for Gaians to get their hands on. In addition to the fact that they are the easiest to harvest from the World Tree, occasionally they will simply fall off the branches of the world tree and plummet through the planes, straight down to Gaia, where they crash into the ground with earth-shattering explosions. While this can be devastating, it usually far and above enriches the surrounding population, once they figure out a way to harvest the heart of the massive seeds. Typically these seeds are about twenty meters in diameter, and the vast majority of the inside of the seed is usable materials, termed "Olneya Wood," for the Elvish name for the stuff.
Crafting Olneya is much like crafting with True Sapwood, requiring long hours of chiseling to reach a specific shape. Once it reaches this shape, it is extremely durable, giving Palladium a run for its money, in addition to being much lighter.
Olneya wood is the easiest of the True woods to work, and the most common to boot. That being said, it is still extremely rare, difficult to work, and absurdly expensive. As such, they typically are only created for extremely important roles. Because of its relation to the world tree, it can be enchanted like almost no other, though mytus wood or mithril is comparable.
Weaponry and Armor
There are no Olneya wood Artifacts on Anoma, though due to how long it has been abandoned, it is very possible that fallen, undiscovered acorns could be found.