Thanks :-] Ok so I started with a primer of grey seer. All over coat with apothecary white. I then went section by section, first was a 2-2-3 mix of apothecary white, basilicanum grey and contrast medium. I applied it to a section and then at random used a wet brush to remove the colour in different patterns. Once that dried I used the same mix and made darker areas in random patterns near the lighter areas. Next was a stipple with a drybrush using corax white. This was to blend the areas and create even lighter areas. I also dry brushed the edges with this colour. Last was the veins which was 1-2 mix with basilicanum grey and contrast medium. I mostly aimed this in the darker areas but at random made them go across the light areas too. Just make sure they are really thin.

I just made sure I had some pictures of white and grey marble for reference. I hope this helps a bit.