CD IS NOT CERAMIC.

CD is is Couche Dure, which is just a hard anodized finish. From Mavic...

"A chimical anodization process that forms a micro-hardness on the surface of the rim


_Slows down wear application by braking
_Improves the characteristics of the aluminum alloy application and the rim last longer
_Makes it easier to build and balance the wheel "

Ceramic is a bit more hardcore.

"
Ceramic 2


By using a plasma beam torch spreading titanium and aluminum oxide powders on the sidewalls of the rim we create a thermal shield that is 30 times harder than aluminum.


_Reduces braking distance by increasing the coefficient of friction between the rim and the brake pads (50% shorter in wet weather)
_Superior resistance to wear
_Reduces heat on rim
_Considered as an external wear indicator "

You can tell the ceramics by the fact the sidewall has a sort of fine sandpapery texture and a dark grey finish. You have to use special brakepads with them (Koolstop Green compound)