Not sure what the source of disagreement is, particulary when my comment was merely to agree with the gp's water analogy when s/he asked:
"What makes a diamond "natural"?"
Diamonds are perceived as luxury goods because of the elaborate fiction of artificial scarcity woven around it by De Beers, which you have acknowledged upthread.
Mentioning gold wasn't necessary because alchemy never delivered on a man-made substitute for gold. And it distracts from the core issue, we are here debating the consequences of the Chinese lab's feat for diamond after all.
EDIT: To summarize, I'm not clear on why you think applying a "luxury goods" lens will lead to better insights as to why people prefer "natural/real" over "man-made/fake" substitutes, when the underlying issue is one of perception, which can be shaped by anyone with an agenda and a marketing budget.
"What makes a diamond "natural"?"
Diamonds are perceived as luxury goods because of the elaborate fiction of artificial scarcity woven around it by De Beers, which you have acknowledged upthread.
Mentioning gold wasn't necessary because alchemy never delivered on a man-made substitute for gold. And it distracts from the core issue, we are here debating the consequences of the Chinese lab's feat for diamond after all.
EDIT: To summarize, I'm not clear on why you think applying a "luxury goods" lens will lead to better insights as to why people prefer "natural/real" over "man-made/fake" substitutes, when the underlying issue is one of perception, which can be shaped by anyone with an agenda and a marketing budget.