What was Isidar Mithrim in the Inheritance series?

Answer 1

Isidar Mithrim is the Sapphire star created by the Dwarves and considered to be a priceless jewel. Though it was destroyed by Arya in the final battle in 'Eragon' Saphira had promised to restore it to its original beauty if the Dwarves were able to locate every single piece of the gem and place them in their original position.

Answer 2

It's not who, it's what. It's the gem in the dwarf stronghold Tronjheim (not sure that's spelled right). Arya and Saphira break through it to save Eragon in the first book, much to the chagrin of the dwarves, but Saphira later melds it back together.

Answer 3

Isidar Mithrim was a giant sapphire gemstone that served as the center of the dragon riders' city of Vroengard in the Inheritance series. It was created by the elven smith Rhunoön and had many magical properties, including being able to store vast amounts of energy.