Mysterious Gem

The Mysterious Gem is a large gem found by The Crossing Guard during their attack on Arrion in Min Dubor. The gem was Arrion's crown jewel, set into his iron crown. It was liberated from its setting by Woadmane, which earned him the name Crownbreaker.
The gem is approximately the size of a cantaloupe; roughly 8 inches in diameter. It weighs approximately 20 pounds, putting it at roughly 45,000 carats. It is an icosahedron, giving it 20 sides. The gem is a vibrant mixture of violet and blue. Its interior appears to be filled with hundreds of thousands of stars scattered through a nebula, helping to give the gem its exotic appearance.
When Nier cast identify on the gem, he determined that it was the physical concept of an idea, specifically some sort of arcane rune.

Weight

20 lbs (45359.2 carats)

Dimensions

8 inches in diameter