What kind of glue?

Epoxy if you can get the existing concrete dry and clean or "ultra flex" thin set mortar.

Thinset or mortar or construction adhesive, and then grout, if you want to fill the gaps between the stones. If it is more than one cinder block, fasten them together. Big-box should have something in the SakCrete aisle that will work for all of it. Are you trying to make it look like a stone column, or just decorate it? If the latter, you could use a stiff mix of mortar or thinset to ice it like a cake, and just press the stones into it once it sets up a couple of minutes.

Play with it- the supplies are cheap, and what have you got to lose? Make sure to buy a pair of rubber gloves, though. Anything cement-based is murder on the hands, and construction adhesive is a pain to scrub off.

I'd use urethane construction adhesive.

Does it have to withstand freezing and thawing, or are you in FL or CA or southcoast of USA?

PC-7 and PC-11 will work. First is dark grey, second white. I'd glue soething else with them first to see if you like the color.

They have loads of uses, and if you keep them separate will keep for a decade or more, so I'd buy the set of 2 4-oz tubes, instead of soemthing smaller. Ace Hardware has them in that size. Home Depot only in a much smaller size, for not much less.

I rented a room once and the kitchen drain was leaking plus the faucet woudn't stop dripping. I applied PC-7 to the wet drain pipe, and kept pushing it back up until it set, in about 5 minutes iirc, and it made a waterproof patch, even while the water had been dripping!

Check out this site for advice on gluing: