Unlike every other metal known since antiquity, gold doesn’t tarnish or oxidize or decay. It’s the very embodiment of purity and immortality. It invokes the divine. If you make something out of gold and you keep it safe, it’ll look pristine indefinitely. This also makes it great as an offering to (the) God(s).

Silver tarnishes, but very slowly and can easily be polished to a mirror finish. This makes it well suited to make “nice” things where gold isn’t necessarily appropriate or cost-effective, and it can be added to gold to bulk it up and improve its material properties without ruining its luster.

Copper tarnishes quickly and forms a green patina in salty sea air, and the vast majority of ancient settlements happened to be on the coast. It’s still a useful metal, but it has to be kept up, a constant reminder of one’s mortality. It’s more suited for tools and cookware than as an offering to God.

Rarity helps a lot with this too, of course. It doesn’t matter how immutable gold is if you can just find it anywhere. This also means it’s great for turning into coinage with your face on it, to remind everyone exactly who’s in charge.

Once upon a time, pure iron used to be even more valuable than gold. Before we learned how to smelt it, pure iron was extremely rare, and the only pure iron that could be found on or in the Earth’s surface came from the heavens (meteoric iron). Finding a pure chunk of iron was tantamount to winning the lottery.

The same goes for aluminum. Despite being one of the most abundant elements in Earth’s crust, pure aluminum almost never occurs naturally. In the 19th century, people had cutlery made out of aluminum because it was fancier than silverware. It only dropped in value once we started to refine it on an industrial scale, which involves electrolyzing molten alumina, requiring an immense amount of power.

Long story short, value is relative. Iron and aluminum got cheap because we figured out how to make more and more of it. Gold and silver remain precious metals because they only got rarer and rarer as more people went looking for them, and their value only went up as we started finding practical uses for them.

I think it’s like this:

Due to their rarity, gold and silver are only available in limited quantities. This makes them suitable as a means of payment, as the limited availability of these materials allows them to have a relatively stable exchange value. They are also durable and easy to work with. So as a means of payment, gold and silver became representative of goods that can be purchased with them.

Coins made of gold or silver, which were used as currencies early on, were not very forgery-proof. However, as the materials themselves are rare, good forgeries were only possible if the material was available. And the rarer the material used, the more forgery-proof the coin became, which is why it made sense to mint coins with a high exchange value from rarer materials (bronze or copper for lower value coins, silver or even gold for coins with higher exchange value).

Early examples of inflation illustrate quite well how value and material are linked: In ancient Rome, for example, silver coins were used as a means of payment. Under Emperor Gallienus, there was massive inflation because he had the silver content of coins reduced to below 5% in order to finance military campaigns and other expenses (he basically created value out of thin air with this move). This ultimately led to a loss of confidence in the currency and thus to a decline in the value of the coins, as they were not inherently forgery-proof (it became quite easy to mint counterfeit coins with such a low silver content).

Still, the value of the material itself has always been variable and depended heavily on its rarity: When the Spanish imported large quantities of silver from their colonies in South America in the 16th century, the value of silver fell because the material became less scarce. This eventually led to massive inflation throughout Europe at the time.

However, the value is not so much determined by the material itself, but by the value that people ascribe to it at a certain time. There are also great historical examples of how speculative bubbles work: In the 17th century, tulip bulbs were at times traded at enormously high prices in the Netherlands because they were difficult to obtain and therefore rare - this made them coveted as a status symbol. However, this bubble finally burst in 1637 when traders could no longer find buyers due to the astronomical tulip bulb prices - demand was covered; the “Tulipmania” had ended. As a result, the merchants began to sell these tulip bulbs in “panic sales” at ever lower prices in order to recoup at least part of their investment. As a result, the price fell to near worthlessness.

Such speculative bubbles still exist today, of course. This is demonstrated very impressively time and again by cryptocurrencies, for example, which are not even material and have no central regulatory authority (such as a central bank) - their value results basically just from what someone is willing to pay at a certain point in time.

So gold and silver were and are valuable not only because of their utility value, but also because of their use as a means of payment, whereby the value - as with today’s currencies - results from a (more or less stable) consensus on the exchange value in goods attributed to a material or currency.

As gold in particular has historically been used as a means of payment for a very long time, most countries still have gold reserves to back their currencies to a certain extent, even if their currencies are generally no longer directly linked to an equivalent value in gold as they used to be. Nevertheless, the US, for example, still holds large amounts of gold at Fort Knox and elsewhere to counteract the fact that paper money, and especially its virtual equivalent in some digital form, is materially worthless.

It looks good. Every culture that’s found gold has made jewellery out of it. The rest follows from there.

It doesn’t tarnish, so once you’ve already decided it looks good, you then notice it doesn’t age or spoil like pretty much everything else. That gives it a magical aura and allure.

It’s fungible (consistent and exchangeable)… gold here looks exactly the same as gold there

It’s malleable - can be easier subdivided into units for exchange. Can readily be worked into attractive decoration.

Although it’s rare this isn’t what drove is attractiveness (the Inca had abundant gold and still chose it to make jewellery out of, it just looks better, even if there’s a lot of it), but scarcity did help it become a reliable store of value across the middle east, africa, asia and europe.

It was valuable because enough people accepted that it was valuable. It’s really that simple. Our money is backed by “the full faith and credit of the US government”. What is that really worth?

I do not have the time to explain the entire labor theory of value to you so you’ll just have to trust me when I say that the labor required for extraction enabled gold and silver to possess a value abstracted from how they can be used. This is known as exchange value and it can only be measured when 2 commodities are prepared. exchange value is quantitative not qualitative so an expression of exchange value looks like: 20yds of linen = 1 coat. This is only true in a society if it takes the same social labor time to produce 20 yards of linen as it does to produce 1 coat, only then are they exchangable. It is the labor that gives them value. So then it may become obvious that having a universal commodity to compare everything to would be useful. Gold fulfills this role well because it is labor intensive to produce (high value due to labor time required), it can easily be divided into smaller and smaller parts to more adequately express precise values, it is rare, and it doesn’t tarnish. Silver is similar but not as rare and tarnishes quicker, both work though.

Copper is abundant and tarnishes quickly