I came across this in Survival in multiplayer, but the effect does seem to also exist in creative single player so i am going to assume this is mod wide

Easier for me to do it in video form
https://www.youtube.com/watch?v=vc9c9WgWht8

As you can see I first placed an Alcara'd Bootes Crystal into the pedestal, with the effect being quite obvious, and the art also being displayed properly.

I then begin to place other crystals into the allready occupied Ritual pedestal. The art on the pedestal changes though the effect of the original Crystal still remains.

Lastly I removed the crystal to show that the original crystal is still placed in the Ritual Pedestal.

what i have forgotten to show was that leaving the world and then joining it again does not bring the crystals back