Extra shell

I have had chickens a long time, and never seen an egg like this.  there have been a few more similar to this, but not as bad.  Chickens have been laying a month or so.  It's always the almost white one.  There have been a few very large eggs the same color, they just look off.  Several times I have found like broken egg with no she'll in the covered area the eggs roll into.  It's not every time, so I'm hoping things will straighten themselves out. Just wondering if anyone has experienced this, or know what is going on.  Thanks

Same thing happened to me twice in the past few weeks...I was reading that it's calcium deposits caused by excess calcium in the chicken's diet. This is my Cuckoo Marans--I'm thinking she likes foraging for plants higher in calcium than the other hens. And I think soil-dwelling insects are pretty high in calcium--especially pill bugs and earthworms. Outside, everything has started popping in the last week and everything is coming alive--Spring is definitely here--and the chickens have been out more eating other things, so I don't think it's a coincidence.

Yup that happens to me too. Not all the time, but once in a while I get a rough egg like that and sometimes I get a shell-less rubbery egg too.