A Crack:

Once solid and whole
Now broken or split,
A fractured surface
With a groove or slit.

It's a thin crevice
A tiny or small gap,
Sometimes hard to see
Or find where it's at.

It's a blemish or defect
It didn't come that way,
But if you fill it in
It goes right away.

It's a slight seperation
Or a shallow break,
That's hard to see
For heaven sake.

It's a chip or dent
That's little in size,
That usually occurs
When we don't realize.

It comes from a drop
A hit or a smack,
From something heavy
You guessed it; it's A Crack.