I’ve started using a manufactured stone installer that seems to be doing very good installation work.  We tyvek our houses, then flashwrap our windows with window flashing.  He then installs felt paper over our tyvek and runs it and the scratch coat of mortar right over the flashed flange of the window.

My question is this:  Should we also caulk the edge between the window and the stone?  Its obviously not a uniform gap, since each stone has different profiles. 

If we should caulk, what do you recommend?  We would want it to be as non visible as possible.

If we don’t caulk, are there any other methods we could use to minimze the potential for water infiltration, or are we doing it already?

Thanks!