Treasure Search

This is a quest with a set of subquests.

Rewards: Mysterious Adventure Box

Treasure search
Required level: 16

Earn 1 Stone through the quick treasure search.

Rewards: 35 xp

Click on the explorer in the star menu to open the explorer window. Select treasure search > Quick treasure search.

The treasure found is random from a number of possibilities, so if he doesn't find stone on the first one or two tries, don't give up. Keep sending him out until he finds it. It's also a good idea to keep sending him out on treasure hunts to add to your resources.