If your eggs have a green ring around the yolk, it means

water for too long, the iron in the yolk reacts with the sulfur in the egg white.
The result is iron sulfide – a gray-green ring that is harmless but visually unsightly.
Hot water and long cooking times are the main culprits of this reaction.
 How to make eggs without a green rim
Starting in cold water

Put the eggs in cold water, it should completely cover continue reading …