Ioun stone

Ioun stones are magical items often manufactured by spellcasters.

Description
When functioning, ioun stones float in a circular pattern around their bearer's head, and grant various benefits based on their color. Two stones of the same type will repel each other. When drained of power, a stone becomes a dull grey, but still possesses the characteristic floating.

History
Congenio Ioun an arcanist of Netheril created the first Ioun stones. They were orginaly called Congenio's Pebbles.