Having thin, excessively pitted or cracked shells may be evidence the snail is unhealthy. It can also mean the snail has been in acidic water long enough to dissolve the shell and weaken it. ... Some snails may be smaller, or some a bit larger, but two inches around is probably most common.

Do snail shells decompose?

After snails die, their shells persist in the environment. Although some shells survive as fossils for hundreds of mil- lions of years, most shells decompose (or effectively disap- pear) more quickly than that, probably on the order of months or years.

How long does it take a snail to repair its shell?

In simple words, the snail uses glands located in its mantle and repair the damage by excreting 'shell substances' necessary to repair the old shell around the broken place. Within a few weeks (usually about 1 or 2 weeks) these cells become fused with calcium and harden the outer coat of the shell.