Runes in good hands.

I have two questions about the walkthrough. 1. Question about Ascha's tear: I can't find where it is because I don't see any similar objects (a round, unclear structure is used as a landmark, but I don't understand what this game object is). Is it always in the same place if I restart the scenario? 2. Question about the quest for the sleeping potion: I've collected 15 ferns, 24 mushrooms, and of course 10 sulfur. I go to the alchemist to make the extract from them, but he says that there are not enough ingredients. What am I doing wrong?