Does onyx scratch easily?

Onyx is made out of bands of chalcedony, a silica-based mineral. While the chalcedony in onyx is rated at either a 6 or a 7 on the Moh’s hardness scale, the rest of the stone is considerably softer. This means that onyx can easily be scratched, causing it to flake and ruin the overall appearance of the natural stone. Do not use onyx tiles in high traffic areas like kitchen counters.