The major reason it has value today beyond it's usefulness is because it historically has had value due to its usefulness. Now it's a self-sufficient, or tautalogical, system - gold is valuable simply because gold is valuable.
Ok, so we are in agreement (but your reasoning is way better):
Gold is an oddity in this regard - it now has a lot more social value than practical value. Thus it is much more likely to experience fluctuation due to human perception more than to supply or demand, which is why normal economic models don't apply.
I like that description.
4Keep in mind, though, that even though it has a high social value, the fact that we still use it industrially at it's insane cost indicates that there really is no other replacement. Its extraordinary properties are well worth the cost for many things, which only reinforces the belief that gold is valuable.
If it were not for its continued usefulness in industry, it would very likely bubble and deflate.
Yeah but we really don't use that much industrially. For scale I found a study that said roughly 320 tons of gold is consumed yearly for industrial uses, compared to the 3800 tons consumed through other sources (against ~2600 tons produced annually). Considering that there is a global supply of close to 130k tonnes we could consume gold for industry at this rate for centuries. Compare that to other precious resources, like oil or (my favorite) Indium.
Indium is the main ingredient of Indium Tin Oxide, which is used for LCD, solar panels, and touch screen manufacturing. Currently ~900 tonnes of Indium are produced annually, and 50% of that goes to ITO production. This is something with a limited supply (mostly coming from China) that has a massively increased industrial application. The price of Indium has risen from 90$ to 900$/kg in the last 10 years (more or less.) And you want to know something REALLY scary? We're projected to run out of it in the next 10 years.
THAT's a mineral with an industrial demand that drives up a price. As an aside though it is crazy toxic so it really couldn't be used for jewelry.
Also, a lot of the industrial usage of gold is simply a marketing gimmick. There are tons of cables and whatnot you can buy out there that have "gold plated" connectors. They are actually gold-plated, but they are done so purely for marketing. They make no significant difference in quality. In most electronic applications you can get away with tin or copper or whatever.