I made some boiled eggs and they were white when they went in! I did water, two inches above the eggs (18 of them). 1/3c Apple cider vinegar, and 1T salt... I was using a cheap Walmart pan as we just moved and I bought it for like $5. It’s really thin. I brought to a boil and then cooked for 11-12 mins.
As you posted a high-res picture, I can clearly see that this is exactly like my grandmother's white eggs would look like after she boiled them in an aluminium kettle. AFAIK they don't sell these any more, so I'm surprised to see eggs like this again after 30 years.
After peeling, the discolouration wasn't noticeable any more.
If both assumptions above (Aluminium pot and not visible any more after peeling) they are safe to eat as Al2O3 is probably the root cause and it's safe according to this document published by the WHO.
I believe the answer about it being mineral deposits to be the correct one. My boiled eggs did this yesterday. The spots look just like yours but they were on the inside of the shell. My raw eggs didn't have them. The eggs were fine, no smell and not old. I had noticed prior that my eggs lately have had calcium deposits on them, and when boiled those spots became dark. It occurred to me this morning that it was likely caused from the boiling process. Maybe those spots were burning, causing the discoloration on the outside and the inside of the eggs. Or it could be a reaction to my hard water or even the tsp of baking soda that I put in the water. Baking soda raises the alkaline level in the egg shell causing it to seperate from the whites for easier peeling. (FYI: It was my first time trying that trick, and it did seem to help.) But ultimately, I've come to the conclusion that the spots are simply deposits that were discolored during the boiling process.
Eggshells can become speckled after cooking due to mineral deposits on the shell. During boiling, the minerals in the water react with the eggshells, causing discoloration. This is more common with hard water, which contains higher levels of minerals like calcium and magnesium. While these speckles may look unusual, they are harmless and do not affect the taste or safety of the eggs. Using filtered or distilled water can help reduce this effect.
