don’t get me wrong sketchfab is unmatched but i think as far as diamonds go these are on the cheaper end, you can do better. the only postpro you might want is bloom, the rest is physical raycasting done in the material itself.
You could get even prettier, i’ve seen an implementation for a more simple one that looks like the sketchfab one too, however any of such effect is not exactly cheap in terms of performance. The shadertoy also isn’t really a reference to test performance since it also raymarches the scene and diamonds, the post effect is a additional pass, and there are cheaper implementations.