Painting White/Grey Stone like the Prospero display board

[Apostle of the 30th Host]

Hi,

 

I am looking to make use of the Age of Sigmar Shattered Dominion bases (https://www.games-workshop.com/en-GB/Shattered-Dominion-25mm-32mm-Round-Bases) to represent Prospero when I build my next 30k army; either Space Wolves or Thousand Sons.

I really don't like the colours they used on the box, but I have an image in my mind of how I would paint it to represent Prospero but I am a little unsure how to go about doing that using GW paints.

 

What I am wanting to achieve is a white/grey stone similar to that on the Prospero display board or Minas Tirith if you're a Lord of the Rings fan (http://battlebunnies.blogspot.co.uk/2016/11/burning-of-prospero-diorama.html), with the arcane symbols either painted the same as though they were carved into the stone or picked out in gold, with the earthen patches painted as sand and the cracks either filled or painted as the damage or orbital bombardment.

 

So if anyone could advise on how to achieve this (both in terms of colours used and a step by step guide) with GW paints it would be greatly appreciated. Alternatively, links to threads / articles where this is covered would also be useful.

 

Thanks! :)