A Hidden Face

Riddle: You use me to hide from the world but they can still see you. Nobody knows but only you do. My exposed side is fake while the other covers your youth. I hold lies and truths in both ways therefore sometimes I am ruth. You wear me with or without your wealth or I can be shaped from wood or chisel and used for stealth. I am never complete without being worn into, for I am a tool that everyone can see, they look at me more than look at you too. I can fake your looks for and from many different things, creatures, objects, insects, and even your fidus achates. It is up to you how I am lune, For I am not the mystery, only though are you. What am I?