Kiplyn is quiet as a mouse. He sneaks ahead to the very limit of the party's torchlight and makes a Listen check. (Assuming he doesn't light a torch, since that would give away his position; 1d6=5, success. Listen check rolled in secret, 1d6=?.) He is sure of it: he definitely hears the sound of 1 large creature, snoring, from the tunnel to the north.
Robur determines the sides of the spire are vertical and slick. The spire fills the room from floor to ceiling. For all you know, you could be looking at a small cross-section of a larger object that is embedded vertically in the earth.
Dame Simonetta touches it, and nothing bad happens. The black stone feels cold and unnatural, like something that "should not be." The owl medallion is not amused (but, as usual, only Dame Simonetta can hear its agitated thrumming).