Ookurikara will come across a red gem outside of Mondstadt. Picking up will result in him receiving a vision (not a Vision) of Dvalin crying these crimson tears. He will also be able to sense Dvalin's great anguish at being forgotten and rejected by someone else.

If he keeps the gem on his person, it will be purified over the course of three days and become a shining Anemo crystal instead.