Gold is an element (atomic number 79), rather than a rock or mineral. A precious metal used in coins, jewelry, and more recently electronics, it has been coveted by humans for thousands of years. On the periodic table, gold is written as “Au”, which comes from the Latin word for gold: aurum. It is highly malleable, and can be beaten into thin sheets of leaf for artistic purposes such as illumination, or as a protective coating in industry. It is
often alloyed with copper or nickel, but in its pure state is non-reactive and does not tarnish upon exposure to air. By adding copper a more red color is achieved (rose gold). Blue with iron, purple with aluminum, and white with palladium, silver, or nickel. Along with the more obvious nuggets, gold is often found naturally as dust or flakes, embedded in rock or quartz.