Jord: Dawn of a World
Alumina trees are native to the Sky Gems, and possess a distinct appearance. While the trunks are a pale metallic brown, they possess no obvious foliage besides their large orange fruit. The fruit ranges in size from about the size of a chicken egg, to larger than a full grown man, and consists of a thick rind covering a large hollow center filled with a flammable gas. As the fruit is edible only by the Windwhales that nest in the Sky Gems, it was only recently that the value of the trees was realized.
The trees have a very tough bark and wood, capable of dulling even the best made saws and axes in short order, and so the trees are almost never felled for construction materials. The trees are also very resistant to fire, even once dried out. Documented investigations have even shown that the trees can put themselves out once the fire burns through the outer bark layer and exposes the thick sap inside to the flame.
That said, the fruit is explosively flammable once the rind is punctured, though the rind itself is both heat and puncture resistant. When a fruit is harvested from an alumina tree is harvested or detached from its host tree, they float gently to the ground, or across the strong wind currents found surrounding the Sky Gems. It is not unusual for detached fruits to occasionally wash up in Tel Seydra’s harbor.
Occasionally, the strong thunderstorms that sweep through the Sky Gems will strike an alumina tree, causing the fruit to explode and flash cooking the tree itself. Nearby trees may also have their fruit explode from the heat released. Often, what remains behind of an alumina tree appears like a metal skeleton of the tree as the wood and sap are instantly smelted by the heat. The metal is lighter than steel for equivalent volume, and stronger by equivalent weight, and has been purposed by both the Malvoli and Voski for use in construction materials.
The Malvoli discovered that the sap of the alumina tree can be carefully purified and refined into a powerful explosive called “Alumina Syrup”, which is used by the Malvoli as the propellant for their firearms. The sap is carefully harvested using taps made of Malvolian Steel in a process not unlike syrup farming, though it takes much longer.
With the aid of the skilled alchemists of Salt, a method of turning the Alumina Syrup into a shaped explosive charge for aid in mining through hard rock was devised.
Attempts to transplant the trees into other areas have failed, and scholar’s attribute the failure to the unique composition of the stone that makes up the Sky Gems.