I have a theory on why gold is considered "valuable."
Yes, it's a good conductor of electricity. But it isn't the best... Silver is.
But silver also tarnishes... Gets that ugly black tarnish on it. And when you clean the tarnish off you are removing silver. Just a fine layer, but you are reducing the amount there. And if the tarnish is bad enough it could appreciably reduce the weight of the silver item. Over time that leads to a loss in investment.
Gold does not tarnish. I can put a pound of gold coins in a clay jar and stash the jar in a cave... And after 1000 years the gold coins will still weigh a pound. There is no loss from corrosion or tarnish.
Gold withstands the ravages of time. Your investment doesn't shrink due to moisture, bugs, dust, acid from skin oils, etc...
If I trade someone for a cord of firewood I only have so much time before my firewood rots. But if someone pays me with a 1 oz gold coin, it doesn't rot. I just have to keep it from being stolen or lost.
That's my own theory as to why gold is considered precious. It can just sit there and hold it's value over time.
Mike