The Heart of Gold

The Heart of Gold

Gold is definitely as cool as the old myths make it sound...

Gold is a chemical element with atomic number 79, and with the symbol Au (comes from the Latin aurum, meaning gold). It is actually one of the highest number elements that can be found naturally. In it’s pure form it is dense yet soft, and is the most malleable (bendable and pliable) of all metals. In fact a nugget 5mm in size can be hammered into a gold foil sheet over 5 square feet in size! Some gold foil can actually be so thin it is semi-transparent. It can also be “taffy pulled” into a wire one single atom think!

Gold is quite hardy when it comes to chemicals. The term “acid test” actually comes from a test that is still used today, where a potential gold material is sunk into a nitric acid solution and only the gold will be left behind due to the acid solubility of most other minerals. As a chemical it is surprisingly non-toxic, in fact gold leaf desserts are quite popular, and even gold-infused drinks. But don’t eat your jewelry!

As of 2019, a total of almost 200,000 tons of Gold exists above ground. That would be equal to a cube larger than some houses! Gold can appear many different tones, but alloys with other metals introduce an even wider color range. In jewelry the ever popular rose gold is made with Copper, and white gold is created with Palladium or Nickel. Even a ‘green gold’ can be created by adding Silver! It can not only be used for jewelry, but also in electronics, and gold foil is used in the helmets of astronauts to reflect harmful sunlight.

Gold is considered one of the four precious metals that has been used in coins, jewelry and other arts in all recorded history. The Gold Standard for currency was in place for many, many, many, many years until the 1970’s when it was replaced for a worldwide standard.

Ancient Greek coin, met museum
Ancient Greek coin, 323-315 BCE, Metropolitan Museum of Art

 

Evidence points to Gold as the first metal that humans used. In fact it’s been found in Paleolithic caves dating to 40,000 BCE, but the first manufactured artifacts come from the pre-dynastic period in Egypt at the end of the 5th millennium BCE. King Tushratta of Egypt actually wrote that Gold was “more plentiful than dirt”. Must have been nice! A couple thousand years later, the European hunt for gold is often indicated as the reason for their conquest of the Americas, which changed the whole shape of human culture (and it must be said caused incalculable damage to native populations).

This ancient obsession has carried on through the ages and is still present in popular culture. Stories like Rumplestiltskin, El Dorado, gold medals and trophies and awards, “the golden rule” or “golden age” perpetuate the idea to this day.

 

Now for some science! Gold is thought to have been produced via supernova and from the collision of stars. Current astronomical models estimate that a single neutron star collision could generate between 3-15 Earth sized masses of Gold! Almost all of the gold present in the Earth during its formation probably sank to the core, so the theory is that various violent surface events like asteroid impacts have since churned it up to the surface.

Gold can actually be manufactured in a laboratory. Attempts at turning lead into Gold go back hundreds or thousands of years...but it wasn’t until the 20th century that the first successful attempt using Mercury was successful. In the mid-20th century it was discovered that the Gold created this way was actually radioactive. So…don’t try this at home.