Thanks all.
Hannes it is just a glass shader with exaggerated settings as you know.
With some careful lighting you could get maybe a better look directly from Terragen.
But here the look comes mostly from postwork.
This is the direct output render below.
The ground is the same as my last work. Just with little changes and the glass shader attached.
https://planetside.co.uk/forums/index.php/topic,28165.0.htmlRender times were 3-4 hours. Without atmosphere and shadows (i think) etc. it renders relatively fast.
With my old pc it would take 5 times longer of course (I love these new AMD CPU's
).
"Raytrace everything" might have a role too. As the rough look on ground is what i wanted anyway.