Cerium Oxide 0.5 micron

I have seen cerium oxide before, but only for use in stone polishing, and at too coarse a grit to be applicable to razor sharpening. Today I have just come across a UK supplier of 0.5 micron cerium oxide powder.
Anybody think this will be comparable to chromium oxide? I just thought that it may be something new to try out.
Nick

http://www.logitech.uk.com/ProductCa...2&idproduct=81

I believe cerium oxide has a mohs hardness of about 6 while chromium oxide has mohs hardness of about 8.5. I believe it's recommended for knife honing/polishing that the abrasive be above 8. But I'm not quite sure.

Justin