Diamonds. They're forever. They're a girl's best friend. They're fancy, elegant, glamourous, and — usually — expensive. But what are they, really, other than solid carbon pulled from the ground? The diamond engagement ring is a staple; a fixture; a sign of true love. Why? Because that's what we've been led to believe. Because there's an entire industry built around this, and that industry is worth a fortune.

The fascinating, highly cinematic documentary "Nothing Last Forever" takes us into the shiny world of diamonds — and specifically pulls back the curtain to reveal that the wizard might be a fake. Director Jason Kohn heads into the heart of the diamond industry and beyond, and reveals that much of what we think about diamonds is bunk. The film also highlights that synthetic — or fake — diamonds have infiltrated the market, growing into a problem that seems almost impossible to solve.

And here's the thing: maybe it doesn't need to be. As multiple people hammer home again and again throughout the course of the documentary, synthetic diamonds can be created to be absolutely identical to real diamonds. Indeed, you can even make a synthetic diamond that's better than a real diamond. But of course, diamond insiders don't want to accept this. They have a profit to be made. They also talk a lot about the purity of the thing, and the sacredness of the experience. In their eyes, you're not just buying a diamond when you buy a diamond engagement ring — you're buying something that is meant to reflect the worth of your partner. More than that, you're buying something natural. "Some people want something that really belongs in the earth," says Martin Rapaport, the exuberant head of the diamond cost-setting Rapaport Group. "Something made by god."

But how accurate is that? "The diamond was never real either," says jewelry designer Aja Raden. "The diamond was always a lie."

A Diamond Is Forever?

"Nothing Last Forever" checks in with several colorful, memorable characters, but Raden stands out the most. She has a kind of scary confidence that practically burns off the screen, and she talks as if she's in the middle of auditioning for a big Broadway show. Smart, fiery, and perhaps more than a little bitter about the industry, she breaks down the many lies and fictions associated with the diamond industry.

Lurking in the background of all of this is the monolithic international diamond corporation De Beers. They run the show, and, according to Raden, more or less made up the entire idea of the diamond engagement ring out of whole cloth — and then sold that fantasy to the public with memorable TV ads (if you grew up in the '90s, you probably remember those ads, which usually featured shadow-people sporting real jewelry on their silhouetted fingers). Then there's Serbian gemologist Dusan Simic, who keeps sounding the alarm about lab-created diamonds infiltrating the market. He thinks he's found a solution to the problem, too, but when he presents it to a group of diamond insiders, they all seem skeptical.

Kohn captures all of this with stark, pictorial images that remind us that documentaries need to stick to a rigid format. Documentaries are still movies, and movies are a visual medium — a fact that many doc filmmakers seem to forget as they merely point and shoot their talking-head subjects. Kohn doesn't give us elaborate recreations with actors as stand-ins, he gives us the real people going about their day but shot as if they're in the middle of a Hollywood movie (there's even a split diopter shot that would make Brian De Palma proud). This heightens the film and gives it even a surreal quality, like during a moment where we see a group of diamond insiders gathered in a Las Vegas penthouse to talk shop. The camera floats around the room, capturing both those engaged in the conversation and bored onlookers who silently wait around in the background. It looks staged and natural at the same exact moment.

From a filmmaking standpoint alone, "Nothing Lasts Forever" is one of the more memorable recent documentaries. But it helps that the narrative being told is so fascinating, scooping us up into this globe-trotting world where money talks and everyone — and every diamond — has a story, true or otherwise.

/Film Rating: 7 out of 10

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