I appreciate your feedback. To answer some of your questions, PGC does do some commercial work in general. I am not sure how engineered stones could be “greener,” as natural stone is 100% natural and can be completely recycled and re-used. Engineered stone is quartz held together by “plastic” and cannot be re-used. I had to do a bit of investigating to answer some of your other questions, as I was not familiar with some of the certifications you mentioned. I directed your comment to Chuck Muehlbauer, Technical Director, of the MIA, Marble Institute of America, and his response was as follows:
If you attend a geology class, like the one we did for StonExpo last week,
you will learn about the geological “Rock Cycle,” which while a lengthy interval, constantly recycles all rock products into different rock
products. Rocks are therefore recyclable and renewable resources.

NSF would certify any given slab of stone, but what they won’t do is certify stone products in their entirety, because since stone is a product of nature there is no guarantee that next month’s shipment of stone performs like this month’s. Manmade products have a quality control that is traceable. The performance as far as cleanability is virtually the same in their new state,
although no testing has been done in the worn state. Engineered stones conceivably would suffer more scratching in service due to the roughly 20% composition of plastics (they advertise 93% quartz, but that’s by weight -
by volume and surface area it is much less than that). Bacteria retention has to do with the smoothness of the surface, so scratches could affect it, although no testing has been done in this regard.”

For more information on granite and green building, you may also refer to the following links:
http://buildingstonemagazine.com/spring-07/green.html
http://texas.construction.com/features/archive/0706_feature1.asp

They are quite interesting and may answer more of your questions.

Thanks!
Barb

James Beameioux