This design would be two pendants, one for each half of the mask (the dark half and the light half.) For materials, I would prefer that it be made of a heavier material, however, the color is more important (For the exact color, refer to the 2nd and third pictures.) The eyes would have to be made of some sort of transparent material, preferably a nice bead/crystal?
For the spiral in the middle, I would refer to the central picture (The one with the glowing eyes) leaving half of the spiral to the darker side, and half to the light. For the chain, I would like this to be necklace sized. I would like the chain for the darker-half to match the light-half material, and the light-half to match the dark-side material (In short, the darker pendant would have a light chain, and the light half would have a dark chain. For the 3D shape, I would like the front to be extruded and have full dimensions (reference picture 4), however, the back should be flat. That said, I would like the back of the pendants to be engraved. For the light-side, I would like there to be the words "Never One" and on the dark-side "Without the Other". The chain should be attacked to the pendant permanently. If you could give me a list of possible materials and their costs for the different sections of the pendants, as well as a general overall price range, that would be great! Let me know of any questions you have please!