Maggie's Farm

The diamond engagement ring on my wife's hand right now is a "hand-me-down", given by my late grandfather to my late grandmother when he asked her to marry him in the early 1920's. I always knew he was ahead of his time, but did not know that he conformed to an advertising trend that didn't even exist until well over a decade later.
Or perhaps things are just overstated a little in the video. While the typical diamond might be "intrinsically worthless", it is not a typical diamond straight out of the mine that one sees attached to a ring. In the same way that the skill and artistry make a faberge egg worth more than it's weight in raw materials would suggest, there is a lot of skill and time that goes into cutting and polishing a raw diamond in such a way as to achieve the goal -- maximum sparkle for that size diamond.
And while it is true that the price of gem diamonds is supported by the cartel and cartels tend to fail, I've seen articles predicting the demise of deBeers going back decades, yet the prediction never seems to come to pass -- even with the more recent ecological and human-rights accusations against the company.
Not that I'd advocate purchasing diamonds as an investment or otherwise. There are alternatives that are just as shiny if that is the desire.