stiff spout on kitchen tap

[boilerbeasty]

i've got a 1/4 turn monoblock tap in the kitchen with a tall swan neck spout which should be easy to swivel around. but its very stiff and i think getting worse. may be that could be limescale ? or a sign of wear and tear ?
if it just needs greasing, can anyone recommend something suitable for use with potable water ?
thanks

 

[ChrisR]

Dismantle if you can find how, then use a descaler if necessary, and use a little silicone grease.