A little bit of The Bay all the way up in Queensland

There's a shell exists on my shelf.
A single perfect shell looks right out of 

The little mermaid.

A little bit of The Bay all the way up in Queensland.

I wonder how many people have a favourite 

   shell?

Besides a book or two it is my oldest possession.

You could say the colour is mat-grey.

I use it for loose change.

Never was there a more perfect shell.

It exists upon my shelf.