(There's no video for iBook X Icons yet. Please contribute to MR and add a video now!)
This is a set of 5 iBook icons, namely: Blueberry, Graphite, Indigo, Key Lime, Tangerine.
iBook_X.sit (115.33 KiB / 118.1 KB)
iBook X Icons / compressed w/ Stuffit
Those are classic Mac OS icons.
Emulating this? It should run fine under: SheepShaver