It means the egg was overcooked.
That green-gray ring is a harmless chemical reaction — not spoilage.
🔬 What actually causes the green ring?
When eggs are cooked too long (or at very high heat):
sulfur in the egg white reacts with iron in the yolk
this forms iron sulfide
which creates the green / gray ring around the yolk
This is a well-known food-science reaction and is also explained in food safety guidance by the
United States Department of Agriculture.
❗Is the egg still safe to eat?
👉 Yes — it is safe to eat.
The green ring:
