The crystal shaped object is the only object in the scene you can see its material the only other thing adding to the scene is the hdri environment map which does not have a sphere in it. Yet there it is like a mirror ball, I’m not use if this a bug, a feature or Materials Gone Wild™… I can include the blend if you want but you will have to supply your own hdri map it seems to happen on all of them.
That’s something you should always do - with any support question…
Other than that: I’m not sure if it is a good idea to feed a Fresnel node into the IOR input of the Glass shader. Glass has AFAIK its own inbuilt Fresnel value, so you’re kind of “doubling” that. Just set the Glass shader’s own IOR to 2.000.
stangesphere.blend (482 KB)
Here’s the blend file it does seem to have to do with the Fresnel node but it even happens if you switch out the glass shader for a refraction shader.
Looks perfectly fine here…
Ah, I found your map. It’s the Fresnel thing interacting with certain elements in your env map. And BTW, of course the Refraction shader acts correspondingly, as it has the same inbuilt Fresnel…
Things I didn’t know, thanks.