Taima
"Looks like an ordinary piece of rock. It's the most ordinary looking rune among its fifteen other brethren. It is rumored to shift its appearance to match the landscape in which its being kept. A sandy stone in the dessert, a slate rock in the mountains, a mossy-stone in the shires.
300 years ago when Guardian Smithsonian fell, it took the Vanguard 26 years to find and retrieve the stone. Not that it had fallen into another's power. If that were the case, it would have been far easier to locate. It was half buried within the mountains of the Spine and nearly lost forever. It was only by fortune that the stone had already called to its next Guardian, Elisa Doormarrow, among the Vanguard searching for it.
The stone is rumored to have shaped the continent of Arethil itself, from the mountains of the Spine to the islands around the Black Bay and even the Drow's underground cities. The stone does far more than move and shape the earth. It is said to restore the vitality of soil itself. And there are other mysteries yet to be unlocked."
- Passage from, A Study of the Runes, by Professor Xavier Kent.