De or het grofzand?

The correct Dutch article is:

het grofzand

How to use grofzand

the grofzandhet grofzand
this grofzanddit grofzand
that grofzanddat grofzand
our grofzandons grofzand
your grofzandjouw grofzand
every grofzandelk grofzand
which grofzand?welk grofzand?
a big grofzand / the big grofzandeen groot grofzand, het grote grofzand