In Illinois we are required to report the type of any insulation observed.
When I '''suspect'' that it's Vermiculite, I note that testing is required for positive identification and to determine the asbestos content (if any), and suggest that the client start here
Current Best Practices for Vermiculite Attic Insulation - May 2003 | Asbestos | US EPA
http://www.epa.gov/asbestos/pubs/ins...nbrochure2.pdf
if they wish to better understand the implications of asbestos containing Vermiculite insulation.
I also recommend that if they wish further advice as to how to proceed that they consult a Licensed Industrial Hygienist with experience in evaluating Vermiculite insulation.
I also note that even if they decide that it's not a concern, they should consider the possibility that it may increase the difficulty of finding a buyer when it's their turn to sell.