you just need to be chilling mann
The enchanted version is called the "Digsite pendant", since it can teleport you to the digsite.
i think you can get it in the digsite or u can get it via a monster drop.
Talk to an Examiner in the building, North of the Digsite
digsite is near varrock, look on your world map.
The first student you are likely to find says he has lost an Animal Skull, pickpocket the Digsite Worker indicated on the map and you will eventually get the skull, return to the student and he will give you the answer to the first question: Earth Science is the study of earth, contents and it's history.
There is a quest called "The Digsite" .It gives you at least 15,000 exp. Its an intermediate kind of quest and its a lot of fun http://runescape.wikia.com/wiki/The_Dig_Site
to get it back you cant
Talk to an examinator (one of the 3 persons walking around inside the building). If this doesnt work, check your questlog, it might hold clues as to what to do next
NO not unless you remember it, Try hard.
No.
It looks like his back basically or if you want to see for yourself try visiting some runescape help sites.
No.