Nautilus Shell from Wandering Trader
Finally, after a lot of waiting, I managed to get hold of the 4 Nautilus Shells that I needed to build a conduit.
I bought with an extra Nautilus Shell and I still have 4 pieces in another house. Now I will be able to build a conduit.
For the Nautilus Shell I paid 25 emeralds and for 5 emeralds I bought blue orchids.