Bathroom floor tiled - cannot remove hard ‘stuff’ when cleaning

[Supernova11]

Hi everyone

I noticed a while ago I’ve got this hard stuff on my bathroom floor.

It almost looks like polyfilla, like someone has been painting and decorating in my bathroom except I haven’t had a tradesman in my bathroom for years.

I wish I could show you a picture but even then, it might hot help. I just cant move it, no matter how much elbow grease I give it. Any idea of products that might help?

Could it be limescale from hard water?

Hard to tell without a picture but might a window scraper do it?

Put vikal on it, leave it for 5 mins. If it's limescale it will wipe away easily