In the series Edit
The gem was first obtained in the goblin hideout in Royal Builders' Hills that had been taken over by the Demon Cult. Silaqui found it in a chest of clothes by the entrance, and decided to take it with her. In Chorofeyre, she paid Wes Pommiliòne to draw out its magic, before taking it to a jeweler's to put it into a necklace.
During the party's journey through the Underdark to find the source of the ithre smuggling ring, Grigore drowned in a fight against a group of Inaid. Having no other gemstones on them, they were forced to use the gem as the material component for Einkill's Revivify spell, and were able to restore Grigore to life.
The user gains a +1 bonus to saving throws while carrying or wearing this gem.