I've made psy tincture - it crystallises as a citrate or tartrate (not if you drink it). Henbane and Fly Agaric would also produce trance states - of a kind. I don't think carving stones would be practical - it would take days to make and the tools have a heavy bluntness that need precise awareness and great physical strength but...

Coooeee!

< sherrat thinks the decorations on grooved ware and some rock art may be 'entoptic' - a range of constant forms widely - and still - produced under trance conditions. >

Highly debatable, it's gotta be said - and is very much substance-dependant. In countless experiments I've done with some of the suggested entoptic-producing plants, utilising various techniques, such visionary content is initial and short-lived. The primary psychedelic visual material is non-entoptic for most of the European plants.

Cheers - Paul