Here's my latest experiment featuring Blender's realtime Eevee engine.
Watch the behind-the-scenes version here:
Materials courtesy of CMV (http://www.cyclesmaterialvault.com).
Some HDRs courtesy of HDRI Haven (http://www.hdrihaven.com).
Marble surface overlays courtesy of Poliigon (http://www.poliigon.com).
Had I rendered these the traditional ray tracing method, it would have taken me weeks. The beauty of realtime. :)