Aluminum's atomic number is 13 and its symbol is Al. This common metal is widely used because it is abundant, lightweight, resistant to tarnish, strong, and flexible. Aluminum is used in many modern-day electronics to provide structure as well as a thermal conductor to prevent electronics from overheating. Although the metal is currently used in many products including soda cans, it was not always so easy to obtain. In the 19th century, aluminum was worth more than gold. It was so precious that it was used to create the pyramid at the apex of the Washington Monument. At the time the monument was created it was the largest piece of aluminum in the world. Aluminum is often alloyed with various elements, such as vanadium and titanium to create various properties, such as high strength or improved machinability. This particular sample of aluminum is pure aluminum and is surprisingly soft compared to most alloys. This display is contained within crystal clear Lucite acrylic.