Artificial diamonds are worth far less than natural diamonds, if Gold could be artificially made in a lab somehow would it be worth less than naturally mined Gold?

The only current way to make gold artificially in in microgram quantities and it is of a radioactive form, not something you would wish to possess. Even if a stable isotope could be produced, it would be discernable from “natural” gold, thus not affected the value of bullion.

diamonds really aren’t valuable anyway… Debeers just monopolizes them and creates artificial scarcity and demand by their advertising campaigns they have been running for decades

It would probably be worth more since it involves a nuclear reaction, not just a chemical reaction.

As @Fiddle_Playing_Creole_Bastard says, the diamond market is based on artificial scarcity. Colored stones are a slightly better investment, but gold bullion is literally the “gold standard” as an inflation hedge.

@Rarebear True that it is much more rare, but possessing it is hazardous to health, unless kept in a lead container, and it decays into a metal that is not gold.

Gold is an element. The only way you’re going to be able to “manufacture” it would be through fusion. This would result in real gold, not artificial gold so the value would be the same as the gold found in nature.

You seem not to understand the nature of diamonds… or economics.

“Natural” brilliant diamonds are valuable because they are relatively scarce and the sources are generally very well controlled by a diamond cartel headed by the DeBeers Corporation and (this is important, too) they are heavily promoted and advertised as “a girl’s best friend”, and “the only stone to have in ‘meaningful’ jewelry”. So DeBeers gets to set the price, and they get your girlfriend / wife / mistress to whine that she has to have a big, brilliant diamond.

Other than brilliants, industrial quality diamonds (with all of the hardness properties, but not the brilliant view) are relatively inexpensive.

Gold, aside from being a relatively scarce element which has historically been used for coinage and “store of value” for millennia, also has a great many industrial (as well as medical / dental) uses and therefore has demand ranging from coinage and jewelry to industrial, medical and electronic applications. And we haven’t figured out yet how to “manufacture” elements (other than the newest elements of the Periodic Table, which are sometimes little more than “theoretical” elements with no known use—or appearance in nature).