You simply need to return to Lumbridge and talk to him again about Myths of the White Lands.
After you have retrieved the "Enchanted stones", all you need to do is speak to Explorer Jack in Lumbridge and give him the stones.
Explorer Jack is found a few squares south-west of the training area in Lumbridge.
There are several NPCs called "Jack". One of them is "Explorer Jack", which you can find north of Lumbridge Castle.
You need to complete the Lumbridge/Draynor Achievment Diary. This can be started by speaking to Explorer Jack.
He is in a building near the general store in Lumbridge. The building that he is in is indicated by the green star that is over it on the minimap.
Go talk to Explorer Jack in lumbridge. You will then be able to start the medium achivement diary. Complete all the tasks. Then go back and speak to Jack and he will award you with a Level 2 explorer ring.
try looking on runehq
It may involve agility.
Explorer Jack can be found next to Lumbridge General Store.
To beat jack on runescape, you need to slide on the ice and bump into him.
Runescape works on both Firefox and Explorer. You have to download Java in order for it to work on either though.
You can find stones Underground. You take the explorer kit and then go underground.