On Sat, 25 Dec 2004 23:46:17 +0100, david thorpe
wrote:

Has anyone ever come across any on their travels - I haven't.

You'll not find it in glasspaper or sandpaper, but silicon carbide
(the black wet & dry stuff) goes to 800 in any car shop, 1200 pretty
easily in a good one, and as fine as 2400 or 3600 if you hunt around.