Even a fork or the bottom of a hot pan can't damage BLANCO SILGRANIT sinks. The colorful, non-porous surface also makes the bowl resistant from all stains, household acids and alkali solutions as well as easy-to-clean. Diamond Silgranit 60/40 Double Bowl Undermount Kitchen Sink - Anthracite Made from the rock hard, SILGRANIT patented surface, the DIAMOND kitchen sink features a smooth surface that is resistant to chips, scratches and heats up to 536°F.A family-owned company, BLANCO was founded over 85 years ago in Germany, and recently celebrated a milestone of 25 years in the United States where we are recognized as a leader in quality, innovation, and unsurpassed service.