18 karat is the hardest-wearing of the high karats. At 75% pure gold and a quarter alloy, it is tough and a touch lighter on the body. That hardness is a kind of freedom: it holds fine detail, keeps a bold shape crisp, and takes the roughest daily wear. So 18 karat gold is for the pieces you mean to live in and never take off. And it is still high karat gold, true gold through and through, built to be lived in.