Sarah J. Maas said this quote
“ By the Valg, three were made,Of the gate-Stone of the Wyrd:Obsidian the gods forbadeAnd stone they greatly feared.In grief, he hid one in the crownOf her he loved so well,To keep with her where she lay downInside the starry cell.The second one was hiddenIn a mountain made of fire,Where all men are forbiddenDespite their great desires.Where the third liesWill never be toldBy voice or tongueOr sum of gold. ”