it's formed from calcium - which is given to the chickens in their diet. The shell is formed around the egg during it's passage along the chicken's body.
why does my 12moth old chicken lay a soft shell egg then i see blood on the outer shell
It is the same as a regular chicken shell.
As they grow, they start to form a new softer shell beneath the outter shell. Once they are too big to stay in their old shell, they shed it, and use the new shell they've grown.
Well, The shell is rather quite fragile but the shell is a little hard.
When an egg is fertilized, and it is incubated (whether by the hen sitting on it, or being kept in a warm box or special chamber), the baby chicken grows inside the shell, and when it is all grown as far as it can grow in the shell, it breaks the shell from the inside, with its beak, and thus, it hatches.
nothing the shell will grow back
No
No, a snails's shell grows with the snail. They grow their own shell/
Nope... They have to shed their outer shell periodically - in order to grow.
yes the shell grows
no it can not. the shell grows with it
yes the shell will grow with the turtle,, but you may be feeding to much ?if its getting to fat