The transparency does currently use absorption distance, but the main transparency color is white.
One of the things that bugs me is the edges of my prism are very transparent. Could that be because of the main transparency color? I can’t figure out how they got the next hard edges in the reference.
Regarding the index of refraction, I tried that at first, but from looking at my reference image, it seems like the refraction is set to 1. I say this because there is a rock that penetrates the prism at the bottom left corner.
I tried to outline below so you can compare it to the original reference.

Am I just imagining it? Or is the index of refraction actually 1 in the reference?