I don't really understand why you put random shades everywhere on your texture for no really good reason. Here's a quick edit on how you should have made your emerald : ![](http://image.noelshack.com/fichiers/2017/24/4/1497551422-emeraltest.png) The colors are not perfect, quick edit as I said, but it's just to show you. Also, try messing around a bit more with the colors, you're mostly editing the brightness, try editing the saturation for a better contrast.