Check out the kitchen forum on Gardenweb. Have seen lots of discussion there on silgranit sinks.

We're getting new countertops and need a new sink. Hoping to avoid stainless steel and have seen a 80% granite product called Silgranit. Anyone have one of these and can offer feedback? Thanks.

This is the manufacturer. http://www.blancoamerica.com/c3/blanco_usa/_www/en/pub/products/product_portfolio/portfolio_silgranit_sinks.cfm