Olive tree petals, vitrified by frost. Tears of true bitterness prevented the cold from withering them completely. Now they are an offering never made, lost in the snow before it could reach the sepulcher of the saint.
Found in Covent of Our Lady of the Charred Visage next to the second Prie Dieu directly before Our Lady of the Charred Visage (NOTE: Found it with Gemino after delivering the olive oil as of v.3.0.32, somebody confirm whether this is always the case). Part of the Gemino questline. When used on the Tomb in the cave after returning the filled Golden Thimble to Gemino, will open a path to reach Saeta Dolorosa.
Well, I remember it with great sorrow. Engracia was one of us, born in Albero like you and me. She was peculiar, however, because every day, after a day gathering olives, she stayed in the mountains while the rest of us left. Some said they had seen her cry, and that's why she stayed among the olive trees, to be alone with her sorrow. Many years of drought razed the land back then, but although the other crops dried up and died, the olive trees on our hill would not: they remained the best harvests, to everyone's surprise. This gave rise to the rumour that the olive trees were being watered by the girl's very tears. One morning, we found the girl dead, leaning on one of the olive trees: whether she died of sorrow we will never know. We buried her in a small cave next to the olive trees where she cried. The next day, the olive trees has withered.