The beauty, scarcity, unique density of gold (no other metal outside the platinum group is so heavy) and the ease with which it could melt, form and be measured made it a natural trading medium. So it turns out that the reason why gold is precious is precisely because it is so chemically uninteresting. A piece of gold may not have any immediate physical value to the person holding it; you cannot eat or drink it, for example. Most would agree that gold has always had value, for all these reasons, as a component of decorative jewelry, a currency at one time and as an investment.
In the 16th century, the discovery of South America and its vast gold deposits caused a huge fall in the value of gold and, therefore, an enormous increase in the price of everything else. From an elementary perspective, gold is the most logical option as a medium of exchange for goods and services. If you put together all the earrings, all the golden rulers, the small traces of gold on each computer chip, each pre-Columbian statuette, each wedding ring and cast it, it is estimated that you would only have a 20-meter cube left or something like that. The relative inertia of gold makes it possible to create an elaborate golden jaguar and be sure that 1000 years later it can be found in the window of a museum in central London, still in perfect condition.
This post is an addition to my post on why gold and blockchain are a perfect match, which can be found here. They argue that in a modern economic environment, paper money is the preferred currency; that gold is only good as a material for making jewelry. But if society agrees to convert gold into coins in a system of exchange for goods, then that currency would assume an instant value. It's tough and rare enough to be used as a marker of value, but there's only a limited amount of gold that humanity can practically access on Earth.
Gold can be something quantitative and tangible, like money, and at the same time it can embody something ephemeral, such as a feeling, even a series of feelings. Alloys and minerals such as bronze, brass and pyrite can pass through it, to a certain extent, but other properties can be used to check if a coin is made of gold or not. Even today, you'll find that many investors will use gold as a form of protection in times of economic crisis. So what exactly made gold so valuable and expensive, and why did several peoples show such interest in converting it into currencies? Surprisingly, it's not so much about the properties of gold, but about those that other elements don't have.
Pure gold is too soft to be a metal, so much so that people used to bite into coins to check for gold. Human tooth enamel has a Mohs hardness of 5, while gold has only 2.5, so teeth can make a dent in a piece of gold, but not a gold-plated coin.