Each anniversary has a corresponding gemstone or metal. If you're shopping for that special gift, use this guide as a start point. From Visually.  Mohs Scale Topar Qua inare Calci 10 Rankings on the Mohs Scale show a comparison of hardness among the minerals. #1 is softest; #10 is hardest. Metals & Gemstones 1st Anniversary 1 st Gold jewelry Classic,...