Physical gold and silver are as liquid as cash in a bank account, but with constant increases in the price of gold driven by investment demand and scarcity, gold generates more income than bank savings. This is especially true during financial crises. Both gold and diamonds are valuable in large part because they are extremely difficult to extract. In addition, each of them requires skilled craftsmen to perfect and create beautiful jewelry and trinkets.
We're not going to go into which one is more difficult to work with simply because they both have their own unique challenges. These materials are not simply pleasing to the eye, but they also have many uses in industry and manufacturing. Gold also has several financial advantages compared to other assets. Gold has no time limit or lifespan; most of the gold found still exists.
Gold is also portable and divisible; dividing it doesn't change its value, unlike other metals, such as diamonds. Finally, gold cannot be counterfeited or inflated; central banks cannot reproduce gold as they do with fiat currencies. Gold can stimulate a subjective personal experience, but it can also be objectified if adopted as an exchange system. Gold is also very rare.
If all the gold in the world were to melt, it would fit within the confines of an Olympic swimming pool. For example, I would value a gold ingot for what a dog is worth if I were to exchange a dog for a gold ingot. You point out that gold is not as liquid as cash, but gold (which is traded on an exchange and is physically held) is easily sold. Others say that countries such as China and Russia are also interested in low gold prices because they want to buy as much physical gold as possible.
Although gold costs thousands of times more per ounce than nickel, it is cheaper to use gold as an anti-corrosion layer than nickel (for use in naval electronics for military use). Even small amounts of gold can substantially improve products, making it worth paying high prices per ounce for gold. But even if you're one of the select few who value gold on its own, this is usually done because gold plays a role. Gold has value because for most of the history of the use of money by mankind, gold and silver have been repeatedly chosen by free markets as the best form of money.
A good example of this is a jeweler who buys gold directly because of the intrinsic properties of gold. Gold is the metal we'll turn to when other forms of currency don't work, which means that gold will always have value in difficult and good times. Their perception that the value of gold increases over the long term is based on the price of gold measured in their favorite paper currency, for example, the U.S. dollar.
The value of gold in this sense is subjective, since each person decides for himself how much gold is worth during the transaction.