Pizza stones are large flat ceramic stones that you bake pizzas on,
you can see examples here
(http://www.finefoodmarketing.com/Sassafras/Super%20%20Stone%20Baking%20Stones/Superstone.html).

I would like to find out how many pizza stones are sold in the US each
year, ie the size of the US 'pizza stone' market. Obviously I am
ideally after a current, specific figure(sales of pizza stones only
and preferably in the last 5 years) however relevant information on
'baking stones' or 'bakeware' sales more generally would also
constitute a valid answer in the absence of a figure relating
specifically to pizza stones.

Thanks!

Dear Pearce Monster, 

Sorry, but all I could find was "Over 300 tons of the patented
hydraulic cement based formula of FibraMent is sold each year to
professional bakers and pizzerias" (source: BakingStone.com
http://www.bakingstone.com/ ).

I hope another Researcher would be more successful, but it is
possible, that such business information is not free to the public,
and if you are truly interested in attaining it, you should consider
financing a business research on the subject (which might cost several
thousands of dollars).