brown jelly disease

[Richard]

If you can stop the infection turbinaria can grow back.

[Instar]

I would at least save some of it if you can, even it that means the chisel method after all else has failed to stop its progress.
If you already had the neomycin going, it might have had a chance but sounds like its going pretty fast and your about to loose the whole thing. In that case I would frag it with the chisel, and dip the good part in a coral dip triple strength or lugols to be safe as well. It might still be worth getting the neomycin to have on hand just in case. Then try to figure out the cause so you can prevent it again or fix whatever is wrong. You can keep a piece with your polyp on it, no need to throw that out, just frag it off and keep it. Good luck, I hope you win against that disaease.

[Instar]

Star polyps will sting stoneys like that and start diseases, so keep the stars back away from things like that.