Crystal material

Hi all,

I want to make a crystal triangular pillar in Blender that’s only lit up on the sides, like the one here posted by someone answering to a thread on Blender Stackexchange

However after spending a day trying to get my crystal to look like that all I end up with is this:

and this

Can someone please help me to get it like the first picture?
Thanks in advance :wink:

Try to use sky texture for the world with strength 0.1 - 0.5.