Gold does not have much intrinsic value (not actually correct anymore, in our modern world gold is used quite a bit in industrial contexts): apart from being shiny, before the 19th century there wasn't much it could be used for. The vast majority of its value was extrinsic and pretty much arbitrary, in its use as part of monetary exchange systems.
Before the 19th century, gold was used for a very important purpose: money. Money is a commodity just like any other, and some things make better monies than others.
What are some characteristics of a good money?
It's divisible. 1 oz. of gold is equal to two 1/2 oz. of gold. Two halves of a diamond are not equal to the intact whole.
It's fungible. Gold coins of the same weight are, for all intents and purposes, the same. The same cannot be said of diamonds or oil.
It resists deterioration/decomposition. (Self-explanatory).
Its rarity/weight/volume characteristics are manageable. You can buy an iPad with a reasonably sized gold coin. The same could not be said of bushels of wheat, lead, stone, oil, etc.
It is relatively easy to identify. This provides anti-counterfeit measures out of the box.
I'm not a gold bug (I own zero gold... not even jewelry), but I do appreciate that it makes complete and total sense that it was used for money for thousands of years. Should 1 oz. of gold be worth $1500? I don't know; I don't follow the market. I do know that gold is extremely valuable due to how well it serves as a medium of exchange, and due to that fact alone.
tl;dr Gold has intrinsic value: it makes a good medium of exchange.
The major difference, of course, is that diamonds are not rare, can be industrially counterfeited, and are easily damaged.
Diamonds, in some way, are the "anti-gold." There is a great game-theoretic reason for why something as completely worthless as diamonds make great engagement rings though: They are something expensive to the male (so he can't repeat the process of proposing very often) - but worthless to the female (so she can't be accused of being a gold digger) - and at the same time sparkly and easy to show off.
> The major difference, of course, is that diamonds are not rare, can be industrially counterfeited, and are easily damaged.
Gold is not rare either. Please re-read my comment, it's about intrinsic and extrinsic value, especially across history. Before modern industrial usages, diamond was all but useless (even worse than gold, if anything) and all of its valuation was extrinsic.
And much like gold's, diamond's intrinsic value has risen in modern times with industrial uses.
> Diamonds, in some way, are the "anti-gold."
Most definitely not. If you want anti-gold, you should look at water instead.
The value of something is how much you can get in return for the thing from a purchaser that you can find. Even "value is what we agree it is" isn't really right, it's what you can concretely get for the thing. (For instance, the fact that a certain Magic the Gathering card is listed in some book for $20 is meaningless if you can't find anyone who will give you more than $5.) There is no other definition of value that's actually useful, but there are plenty of others out there that will lead you astray.
But at least money exists for the purpose of arbitrarily representing "real value". Gold has some real value, it's just quite a bit less than the value we've given it.
