There is no doubt that gold is a beautiful and popular precious metal, especially for making jewelry. But there is a downside to it: Gold scratches easily. That is why old gold jewelry starts to look beat up.
People have tried mixing gold with other metals. These alloys can be harder but the quality of the gold is always reduced. Now Swiss scientists have figured out how to make 18kt gold that is also extremely tough and durable. Basically, they mix it at the nano scale with boron carbide, a ceramic used in bullet-proof vests, to make a composite. Read the full article.