As you can see in the chart, Diamond is the only thing you’d recognize which is harder than Tungsten Carbide. Gold as you know is a softer metal which is why it only scores a six on the mohs scale. This is why you’ll notice gold rings getting scratched, having any hard edges smoothed over as time goes on and generally losing that ‘new’ appearance. In fact, the harder variations of gold are LESS pure, meaning if you want it to last you will have to choose an alloy anyways.
Tungsten Carbide is looking really good again isn’t it?
This post answers the questions: How hard is Tungsten Carbide? How hard is gold? How hard are diamonds? How is hardness measured? What is the Mohs scale?