Synthesizing level 50 legend stones

[Conseq]

Can you synthesize level 40 legend stones into level 50 ones? And how many does it take?

I couldn't find a list of all the things you can synthesize as you level up.

[Aeodrin]

Cannot synth 40 to 50 legend stones. If you are already 50 just open up the smith and go to synth, it shows all you can synth. Without the recipe for higher lvl gems you won't see those on your list btw.