James Pustejovsky's (in the context of discussing polysemy) book also examines mass and count nouns in his text The Generative Lexicon. Pustejovsky sets forth a few examples of mass and count nouns that I want to present. He writes that sand, "although in fact composed of individual grains," is a mass noun because it refers to "undifferentiated stuff in our daily experience of it" (Pustejovsky 17). But the word "house" (he writes) "is obviously perceivable as an individuated object and is classified as a count noun."
Pustejovsky goes on to provide the following examples:
Mass nouns: much sand, more water.
Count nouns: several houses, every child.
Examples of nouns which are both mass and count simultaneously are
1a. Texans drink a lot of beer.
1b. Patsy relished every beer she drank.
2a. More e-mail is arriving every day.
2b. Every e-mail I send gets bounced.
From Pustejovsky's discussion, it seems that he classifies mass/count nouns
on the basis of individuation potential.