Sulphur Pile

There are just a few things
that i know about the sulphur pile

first, is that i am not sure it is actually sulphur
second, the pile is not harmed by rain
next, the (assumed) sulphur is used for something
somehwere else
trains bring it here, ships take it somewhere beyond

and the pile never changes in size

glowing like Van Gogh's pool table
under cafe lamps