Geez I made a lot of changes and additions here. For starters I altered the stone colors a bit, making them each a little bit different from each other as well. I added a specular map, altered the emissive slightly, and added normals. I also changed the gem color and am still deciding on messing with it further.
Making an enemy spawning portal for my senior project. The reason the chain placement seems a bit off is because it looks right from top down, the primary way you will be viewing it. It currently has no specular or normals but I'll get to those. It also uses an emissive and in this render there is a purple area light underneath the portal.
Edit: Also thinking of making the gem a more lavender/amethyst shade so it doesnt "blend in" to the portal below it.