Pitch black button quail egg on candling

[PrincessKiara]

There was a button quail egg I thought might be an early quitter. I didn't see veins or anything much...then today day 7 and since two days ago bam it's all black except for the air cell and a small distance around it? I couldn't see any movement, but I didn't look too hard so as not to chill a possible chick. What gives?

 

[R2elk]

There was a button quail egg I thought might be an early quitter. I didn't see veins or anything much...then today day 7 and since two days ago bam it's all black except for the air cell and a small distance around it? I couldn't see any movement, but I didn't look too hard so as not to chill a possible chick. What gives?

Sounds like a rotten egg to me.