Mithrus is the Dwarven legendary gemstone, one of the Tears of Esk.
History
Mithrus was gifted by the gods to the dwarves in order to show that they did not favor either the elves or the dwarves more. Instead, it was used as a weapon of mass destruction against the elves in response to Veladriel Dawnwalker's use of Ilterendi against the dwarves. When the two factions seemed like they would destroy each other, the gods created humans to bridge the gap between the two nations.
Mithrus controls the earth. Entire armies have been swallowed by it's might. The gemstone was later attempted to be combined with Ilterendi, but the Dark Dwarves stole the two gemstones, starting a war between the elves and the dwarves. It was not until King Lokkhan was able to return Ilterendi, that the war was finally put to an end.
Current Status
Some rumors claim that Mithrus was never returned to the dwarves' possession. Others claim it has been used to cause Mok'gram to erupt again. Some claim that it rests safely in the crown of the Dwarven queen, Tristia Renbran. Time will tell where the gem lies.
OOC Knowledge
The stone is destroyed. It was taken to Isandor and used to re-erupt Mok'gram.