My Stone Encased Pillow

My stone encased pillow
So cold inside my chest
Hard as diamond
The stone never breaks
It protects
My stone
My stone encased pillow

A crack, a crack
A crack in the stone
How can this be?
A crack in the stone
It was so strong
So strong
But a crack
Who is so strong
They know so much
They want my stone
My stone encased pillow

I cant let them in
It hurts, so much
Too strong, my pillows
My pillow it shows
My pillow it shines
My stone it shatters
My pillow there to see
♠ ♠ ♠
I wrote this cause well its what i feel.
Bonus points to whomever can say what the Stone Encased Pillow Is