spots (bubbles) on eggshell

[camotruck]

Does anyone know what the deal is with these spots on the egg? They are hard just like the shell. Just want to make sure its ok.

 

[ChicKat]

It looks to me like an irregular deposit of calcium on the egg shell. Generally it is nothing to worry about. It could be that the chicken encountered some small stress during a certain part of her egg making process----

Here are a couple of links about irregular shells
https://www.backyardchickens.com/t/239852/why-am-i-getting-warty-eggs-any-one-know/10
https://www.backyardchickens.com/t/642945/free-ranging-and-warty-eggs
http://club.omlet.co.uk/forum/viewtopic.php?f=37&t=25090

You may be able to find more info. with a google search and perhaps some BYC experts will chip in.... :0)