This stand I made to suit a table lamp project my mum had going on.
There's just a hole drilled in the base of the glass brick with a diamond hole saw to allow the led sting lights into the brick.

It suits 200x200mm glass bricks (the type glued from 2 halves).

It has a little recess as you can see for one of those twin pack aa battery holders.

Not too sure if the other styles have the same concave profile on the edges like these ones we just happened to have them laying around.
You may run into issues if your glass brick is one solid piece as it might not leave room for the led string to run though (if that's what you actually doing)

I printed this out on 10% infill in PLA as it doesn't have any need to be super strong - it's just going to to sit on a table and look pretty.