Well then;
1.) The chest actually contains the Bauble stick. You have to
use the bauble stick, to get the under water crystal. (click on the USE/GIVE icon..click on use..scroll down, until the stick appears..click on the crystal)...
.. there is also a key thats out of reach...remember where it is. You'll be able to reach it later in the game, when you get to the
tombs .
2.) The crystal is used to get you into the tomb of F'lokis Ra.
( accessed by an elevator, back in the room with the broken stairs.)
3.) Kill F'lokis to get
his neckless. (?locket?) You'll need it when you talk to Kerah's statue. (right click on the locket..click on the scroll, to read)
4.) Before you leave F'lokis..Remember what Rathpian said about the secret chamber
above his tomb..Send the elevator down, but get off before it moves..When it comes back up, jump on top.
As for the other amulet. If it's a big green, winged thing, It's algamesh's amulet. Later on, you can trade it to Kerielle for some potion. The potion is supposed to help you kill Elyssia, in the serpent temple, but the amulet is ...AC + 1..protect poison 50%..Cure poison spell, 3 charges... So, you can trade it or wear it. It's up to you.. (I forgot to use the potion and was still able to kill her.)
Hope this helps...keep us posted.