The grammar of 实事求是的石 I actually want a tongue twister for practice.  But I want one that could be a Chinese sentence. Is the following at all acceptable as way to say "This is the 'seek truth through facts' rock"?

这就是实事求是的石.  

By that I mean the rock on the Renmin University campus with the motto 实事求是.

On line I find nearly this, but always with 石额 or some other noun complement to 石.  Can I possibly do without that, or is 石 too much of a bound morpheme to allow that?
It's okay grammatically, but not very challenging. 

粗俗書生私下心想，「石上書寫『實事求是』四字似是敘寫世上數億心上思想，實屬喜事!」