I picked one of these up a long while ago and it sat primed for a long time. I was inspired to try painting a large marble statue on each facing and started on it. I'm done half of it, and it's really annoying so I'm sure it will be a while before I revisit this. Also since I can't fit it in a display cabinet and I haven't played a game in forever, It will probably continue unfinished for the foreseeable future, until I have a place to put it. Such a huge model though. I air brushed dhenab stone, wych flesh and elven flesh in strips across the statue. After this was dry, I used hormagaunt purple to paint cracks and lines in random wiggly lines, and watered down to give the effect it was at various depths in the rock. I tried to keep a predominant direction to the grain. After this was done, I watered down some gryphonne sepia and washed the whole piece. As this was drying, I flipped the model upside down, then right side up every minute or so to move the pools around. This cause some random drying effects. Once this was near dry, I used a slightly wet dry brush to scrub off the dried wash rings in certain areas so that again, it didn't just look like dried paint rings, but subtle colours in the rock. I've seen way better marble effect on other people's models but for a model this large that isn't all flat surfaces I don't think I could even hope to emulate those techniques. From 24 inches away, I'm content though.
I do want to share this tutorial I found online, this guy's marble effect looks incredible and shames mine http://www.warseer.com/forums/showthread.php?407897-Brother-Josef-desecrates-a-Chaos-Shrine-(diorama)