What part of what shellfish is this?

[Dansvidania]

Hello everyone,

I found these.. shells (maybe?) a long while ago and I forgot where and what it was. Do you know what this things are?

 

[Humpback]

Belgian chocolate seashell

 

[redneck]

Belgian chocolate seashell

Lol ..........

 

[Goatboy]

Look like they've been worn down in the surf but unusually flatly.

 

[JonathanD]

Need better pictures from other angles to determine what they are.

 

[Dansvidania]

Thank you all for your answers

The following is my best try to provide some better quality pictures, but my phone is the only camera I have and as you might have noticed It is not that good.

So the 3 objects are somewhat flat pieces of what I guess is mother of pearl, they look like a Fibonacci spiral on both the white side and the shiny orange side. It does not look like they are hallow anywhere, there is no opening like one would expect to see in a snail shell.

https://dl.dropboxusercontent.com/u/21908560/2014-09-07 19.50.11.jpg
https://dl.dropboxusercontent.com/u/21908560/2014-09-07 19.51.01.jpg
https://dl.dropboxusercontent.com/u/21908560/2014-09-07 19.51.15.jpg
https://dl.dropboxusercontent.com/u/21908560/2014-09-07 19.51.26.jpg
https://dl.dropboxusercontent.com/u/21908560/2014-09-07 19.52.04.jpg
https://dl.dropboxusercontent.com/u/21908560/2014-09-07 19.52.09.jpg
https://dl.dropboxusercontent.com/u/21908560/2014-09-07 19.53.19.jpg