The Iron Oak

The Iron Oak was a piece of radioactive metal that came from a meteor. It was found by the Westlo Elves many centuries before the foundation of Duntown and the start of the modern age. Working with the Westlo Orcs, the elves of Hollymargret managed to find ways to contain and to focus the power of the Iron Oak, creating, for example, light that endured without fire or sunshine, warmth without using fuel, and a weapon that could not be defended against.
Laeneth the elf is credited with discovering the item, Gristle the orc with being the first to use it, and Maguffin the First of Hollymargret (and Sixth of Holly) being the King who managed to contain it.

Utility

As stated above, the Iron Oak seems to have been used to provide hot water and light for the city of Hollymargret. Whether it was also used to drive machinery or a turbine is not known. What can be deciphered from the legends is that it could be used as a weapon, and that this use was discovered accidentally.
A series of lenses constructed and polished by the elves were placed in line with a pinhole chink in the box of the Iron Oak. A goblin lab assistant was accidentally denatured by the resultant beam, and some of the stone in the wall began to melt.

Access & Availability

If the legend above is partly true, we can assume that there was no access to the radioactive material, and that the orc engineers would have constructed a box of lead or other relatively inert metal to house it.

Discovery

The Iron Oak fell from the sky at some date long before the modern era. The precise date is not recorded, nor is the precise location known. Legend has it that it was somewhere in The Wilds, perhaps in The Thicket. Unfortunately, we only have oral history to rely on in terms of the discovery of the object, and the following story bears many hallmarks of legend.
Alerted by 'a star falling in the forest', an elf called Laerneth found the shining metal core, which had apparently solidified in a shape reminiscent of a winter oak, with branches forking out from a central trunk. She was taken by the beauty of the metal, but could not touch it. 
As the elves of Westlo did not work metal at this time, she called on a neighbour. Gristle was an orc, skilled with forges and iron work. Gristle and Laerneth together visited the place where the meteor had fallen, and they found it was warm to the touch but did not burn them.
Taking it back to their village, they found that the metal was capable of heating water for cooking. It also gave off a faint light. In a very short time, Gristle and Laeneth's friendship blossomed into love and they were married. They were said to be the first orc and elf to be wed in Westlo.  
While the union brought the two communities close, it was the tragedy that followed that brought them closer. Gristle and Laeneth did not see the anniversary of their wedding, and a sickness came upon the village. Suspicion eventually fell on the Iron Oak, and it came into the keeping of the leaders of the community.
Orc and elf worked together to control the power of the item, and rather than destroy or otherwise contain the Iron Oak, it was resolved to make use of it. It was placed in a room in the elven village of Holly, and the orcs brought engineers and craftsfolk to construct a safe container for it: it heated the water, powered lights and gladdened the hearts of the people, who knew only that its magic was contained.
The orcish village of Margret was unified with Holly, and both peoples grew together in safety and prosperity.