Oh dear - it's more complicated than reflecting the laser onto the prism.
Two symbols - and turning the gear reveals two different ones.
You're not totally in the dark, though! The fairy scholar's notes should be useful here.
You can 'use' the notes on the symbols to see what they represent in the fairies' world.
The bricks mean 'solid' - all that is solid in the world. The moon means 'magical'.
It means we need to put something in the basin that is both solid and magical.
Unfortunately, no - but if we fixed something with our magic, that would probably meet the criteria.
Look for something in the cave that's small enought to fit in the basin, and is also broken.
Near the peacock statue is a broken lamp; repair it with your magic and put it in the basin.
One out of three basins filled - turn the contraption's gear to see what's next.
The beetle represents all of the 'living'. The bird represents all of the 'floating' things in the world.
Don't panic if Geron suddenly starts speaking German when examining the bird - I had the same bug!
In a roundabout way, it seems the basin needs a living, floating creature - like a fly.
You'll find one in the cave.
We have a net!
The dragonfly doesn't know that! Throw the hammock at it.
Don't forget to fill the basin before turning the gear again.
The water represents 'the liquid'. The fire represents 'the burning'.
We need to gather some liquid that can burn - no, not alcohol.
Just like the other two, you'll find it in the cave.
Something that you wouldn't want to throw on a fire - a liquid that can be used to start them, too.
Remember that you can gather liquids with your water bladder.
Gather some of the lamp oil on the left side of the cave with your water bladder.
You'll then need to light it with the flintstone and tinder.
We've solved the riddle! Twist the prism and behold - Fanglaria!