There comes a point in the life of every foldable smartphone when, after a wave of hype and highly controlled early looks, the phone actually hits the hands of the general public—and durability issues immediately pop up. We've seen it with the Galaxy Fold, which died in the hands of reviewers and was delayed for six months; the Huawei Mate X, which had its launch limited to China and broke after a single drop; and the Moto Razr, which has a creaky hinge that jams easily and a display that delaminates. This weekend it was the Samsung Galaxy Z Flip's turn to disappoint us. The initial shipments are going out, and we're already seeing that Samsung's much-hyped flexible glass cover isn't much more durable than plastic.

YouTuber JerryRigEverything regularly does destructive durability tests on phones, partly by attacking a device with a set of Mohs picks. These pointy metal tools that are calibrated to the Mohs scale of mineral hardness allow a user to determine the hardness of a surface by doing a scratch test. You start with the softest pick and work your way up the set until you find something that can scratch the surface you're testing. A modern smartphone with Corning's Gorilla Glass scratches at level 6 on the Mohs hardness scale.

The Galaxy Z Flip features a first-of-its-kind flexible glass cover that Samsung calls "Ultra-Thin Glass." Until now, foldables have had to suffer through life with plastic display covers, which scratch easily, don't provide much protection, and just like a resistive touchscreen, feel bad to swipe around on, thanks to the squishy pliability of the display. With this new invention of flexible glass, the Z Flip promised a return to a hard, smooth, scratch-resistant display surface.

So how did the Z Flip fare against JerryRigEverything's Mohs picks? It scratches at level 2, the same level as the plastic-covered Galaxy Fold and Moto Razr. You can actually leave marks on the surface with a fingernail! This is not what Samsung was promising.

Samsung sent The Verge a response to the video, reiterating that the display is actually "glass." "Galaxy Z Flip features an Infinity Flex Display with Samsung’s Ultra Thin Glass (UTG) to deliver a sleek, premium look and offer an immersive viewing experience," Samsung told the site. "Samsung’s first-of-its-kind UTG technology is different from other Galaxy flagship devices. While the display does bend, it should be handled with care. Also, Galaxy Z Flip has a protective layer on top of the UTG similar to Galaxy Fold."

Samsung's official Z Flip videos show this "protective layer" going on top of the glass display; presumably, it's made of plastic. This layer is not removable, though, so any scratches to the top plastic layer are still scratches the user has to deal with forever. What's more worrying is that JerryRigEverything's video shows that the underlying "glass" layer doesn't provide protection from punctures, either. The Mohs picks were able to easily puncture both layers of the display cover and damage the underlying pixels, which wouldn't happen with a normal glass cover.

Received my Samsung Galaxy Z Flip just now. Opened the box. Removed the protective/instruction film. Flipped the phone as you would do since it’s a flip phone and this happened. I heard the crack as well. 😰 cold weather?#SamsungGalaxy #ZFlip #samsung pic.twitter.com/j8KLL2vm8d — Amir 💎 (@mondoir) February 14, 2020

Even though the phone failed the scratch test, that's not to say the display doesn't share any properties with glass. One Twitter user cracked their Galaxy Z Flip on the first fold, possibly due to cold weather. So we know it can shatter, at least.

Samsung hasn't officially said who makes the "Ultra Thin Glass" it uses as a cover for the Z Flip. Samsung recently became the biggest shareholder of Dowoo Insys, a company that makes ultra-thin glass, and reports from reports from Korean media say the Z Flip uses a combination of Dowoo technology and glass from Schott. We're still waiting for the industry leader in smartphone display covers, Corning, to release its own version of flexible glass, which the company says it is working on.