From Lost Fables Wiki
Etes H'evelm's Sapwood is nigh-indestructible, requiring cutting tools made of equally mythical materials to harvest. Though it is more common than the heartwood of the same tree, it is still unbelievably rare, as travelling to the world tree is neither easy nor safe, let alone getting through its 200 meter thick bark and harvesting the wood at the center. That being said, several expeditions have been successfully led, leading to very small amounts of the wood getting out into the wider world of Gaia.
True Sapwood must be slowly whittled and chiseled by a blade of at least mithril's hardness and ability to hold an edge. Only this way can it be formed into a proper tool, but if it is so chiseled, it becomes almost indestructible, and almost as willing and capable of taking enchantments as True Heartwood.
Almost any tool can be improved by replacing its wooden pieces with True Sapwood, or even the working end itself. It is very light and exceedingly strong, making it a naturalistic form of mithral.
Weaponry and Armor
Extremely high quality pieces of armor and whole weapons can be crafted from this, if enough of the wood can be found to make such pieces.
There are no True Sapwood Artifacts on Anoma, nor any known ways to get it. Perhaps you can change this.