Gold is the most logical choice for a medium of exchange for goods and services. The metal is abundant enough to create coins but rare enough so that not everyone can produce them. Gold doesn't corrode, providing a sustainable store of value, and humans are physically and emotionally drawn to it. Societies and economies have placed value on gold, thus perpetuating its worth. Gold is the metal we'll all fall back on when other forms of currency don't work, which means that gold will always have value in tough as well as good times. 
What Makes Gold so Great?
Aug.27.– Gold has long been considered the king of metals, but why? What makes this lustrous material so alluring? Why does it remain so valuable?
From a purely practical standpoint, gold has a lot of desirable properties.
For one, it’s durable—it does not tarnish or rust. In fact, it’s one of the least reactive elements on the periodic table. That’s why golden relics from ancient times stay so well preserved.
Artisans throughout history have always revered gold because it’s relatively easy to shape and bend. You can mold ornate designs in gold without breaking it—making it an ideal material for jewelry and decorative flourishes. Gold is also non-toxic, which is why it has been used in dentistry for so long.
Gold has since found new uses. NASA, for example, puts a gold coating on space-bound vehicles to reflect the sun’s radiation and keep equipment cool. Astronauts’ helmets are also coated with a thin gold layer to shield space travelers from the sun’s harmful rays.
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