It depends on the knife. Regular steel knives will not scratch it. Certain stainless steel knives will depending on the carbon content.Originally Posted by GSdub510
And it also depends on the amount of quartz that is present in the glass mixture. Quartz makes glass stronger.
The main draw of Gorilla glass and similar tempered glasses is the pressure resistance. Meaning that if you sit on it or press up against something it won't crack as easily.