When one thinks of precious metals, Gold is often first to come to mind. The craze for gold was responsible for the California gold rush of 1848 in which approximately 300,000 people traveled to California to fill their pockets with the valuable metal. Often we think of gold as being a material of wealth, in jewelry or artistic creations, or as currency; but gold must also be considered as an element, taking the 79th position on the periodic table of elements. From a chemist’s viewpoint, gold is also a very interesting metal worthy of attention.
Gold possesses many unique properties that have valuable use to an industrialized society. For instance, it is the only metal that will not form an oxide at room temperature, meaning that exposure to air will not cause gold to rust or tarnish. Surprisingly, it is also the only yellow metal. The high electrical conductivity of gold makes it an excellent conductor and is used in many electronics, such as the circuitry involved in mechanical air bags in vehicles. The metal is also very malleable, meaning that it can easily be shaped and stretched without breaking. It is considered the most malleable metal in the world, being able to be stretched into sheets thin enough to allow light to penetrate.
Gold also possesses an astounding ability to reflect almost 100% of infrared waves, which earned it the role of visual protection for astronauts on the Apollo 11 moon landing mission.
About 80% of gold production is used in jewelry; however other common uses are as electrical conductors, medical procedures, and as a dye. Approximately 0.000000005 percent of the earth is composed of gold, making it the 75th most abundant compound of the earth’s crust. Large gold deposits have been discovered in South Africa, Australia, and western North America.
Gold is the second most valuable metal purchasable on a global scale. Behind platinum, at around $1500 per ounce, gold is valued around $1200 per ounce and changes often. Discovered around 3000 BC, it is seen in some of the earliest man-made arts and was often used in ancient Egypt in tomb production.
From a chemical approach, gold is a transition metal about 19 times as dense as water. It melts at 1064 degrees Celsius and boils at 2856 degrees Celsius. Gold crystals are seen in a cubic arrangement and have only one stable isotope, AU 197. The standard atomic mass of Gold is around 196.
