The water texture? @michelegargiulo this happens in a client block highlight event, I think it might be happening late or too early and causing this

@MsRandom I did some tests where I tried to mess with both event priority and blend function.

I suspect that this happens because water is also rendered as a Shader, and the result of both shaders does not blend correctly, and the Alpha of the talisman predominates over the water one. This is a brute force test, trying all the possible combinations of SourceFactor and DestFactor in the GlStateManager.blendFunc, and it seems that there's no combination that really fixes the issue.
Event priority does not seem to have any effect. Any other ideas?

To be honest, this in vanilla has been unresolved for years - https://bugs.mojang.com/browse/MC-162693

Closing, as this is most likely a Vanilla bug, and thus outside the scope of this mod