Thalia:
My request is not a difficult one. A special fertilizer is needed to maintain the green health of the Mother Trees that we look after. This fertilizer is made from the leaves that fall from the trees in the Elven Forest.
Have you ever seen any fallen leaves in the Elven Forest? Probably not. That is because the dryad elders collect them even before the leaves have had a chance to settle on the ground. They gather these leaves and turn them into golden leaves. Use these golden leaves as fertilizer, and the trees of the Human world will never have to be fertilized again.
Take this sap with you and slay dryad elders to obtain the golden leaf in its possession. Bring back 5 golden leaves and I will tell you the whereabouts of the aquamarine.