Ah, I recalled see'ing a pic of a BluRay disc long ago and it looked way different than the norm disc (was a smaller CD inside of a squared disc-holder thingey, in the size of a usual floppy disc I believe)
That sounds like a mini-disc, not BluRay. mini-disc is another format sony created, but it never caught on with the mainstream and kind of fizzled out.
BluRay has the exact same size and shape disc as a CD, DVD or HD-DVD... only difference between all of these is that the color may look a little different.