Jewel of Jerrimore is a legend that can trace its origins to the third century Before Entharion the Wise in the northlands of Frobozz.
This jewel is mostly a star sapphire, said to have been the greatest treasure of the Mage of Jerrimore. As he lay upon his deathbed, believing that his enemies poisoned him, he put a curse on the Jewel and its possessors.
After the Mage's death, each of his heirs took the jewel; each held it jealously, mistrusting any who might look upon it; each became obsessed with the greed and treachery they perceived around them; and each came to early and horrible deaths. Thus grew the legend of the cursed Jewel.
Although the legends vary, all versions say that the Jewel traveled through many lands, always leaving a wake of misery and death, and became lost for many years in an iron mine near the Flathead Fjord. The entrance to the iron mine is marked by a warning of inevitable death to anyone who takes the Jewel.
In the year 883 GUE the First Dungeon Master entered the iron mine to take the sapphire, using it as part of a spell that summoned a key to Megaboz's trunk.