Why our necklace?
High Resolution Design Pattern for Printing where you can clearly see the details inside this Cabochon Necklace.

Things you may not know:
Writer Marc Guggenheim recently told Comic Book Movie that as the film's conclusion is open-ended, there is the potential of a return later down the line.
The ending of Trollhunters: Rise of the Titans perfectly sets up a new set of stories as Toby taking Jim's place could potentially see a whole raft of different events take place in this new timeline instead of the story that we already know.
Whether or not this ends up happening remains to be seen but if this is indeed the end of the Tales of Arcadia franchise, what a run it's been.
So, we're as fandom.. Let's hope!!