Sapphire glass is the latest buzz in smartphone technology. This synthetically produced sapphire is only chemically related to mined gemstones that share its name. Discover why today’s smartphones are increasingly embracing sapphire glass for their displays.
What is sapphire glass?
Sapphire glass is an artificially created sapphire created in a lab. While sapphire gems are known for their blue coloring, the glass is clear. The color comes from impurities in the blue stone. When scientists make sapphire in a lab, it’s in the purest form possible, so it is transparent. The synthetic manufacturing process produces a crystal that is only surpassed by diamonds in hardness.
How is sapphire glass made?
Sapphire glass starts out as aluminum oxide powder. Putting this powder under heat and stress, like the natural processes that create gems, forms the sapphire crystal. But after formation, the crystal is not in the thin sheets needed for smartphones and similar applications — it needs to be cut. To ensure the sapphire cuts cleanly into sheets, manufacturers apply more heat that rids the crystal of any internal strain that could crack the material.
Apple cuts the crystal with a diamond-coated wire into sheets thin enough for use on the cover of a camera lens and the TouchID cover. Machining cuts the crystal sheets to size, and hours of polishing produces the desired effect of a clear, scratch-resistant glass covering. These coverings are used in many technological applications, from high-end watch faces to the covers of barcode readers at your grocery store to smartphone faces.
Watch this video about the manufacture of sapphire glass for a smartphone display:
Why is sapphire glass good for smartphones?
Smartphones are subjected to daily stress — you drop, scratch, touch, press and swipe the faces multiple times with each use. A smartphone glass must protect the face from scratches, which can obscure the display over time. Sapphire glass is highly scratch-resistant, almost to the point of being scratch-proof.
Sapphire glass has other advantages beyond just its ability to resist scratches. Manufactured sapphire is exceptionally durable in elevated temperatures. It’s thermally stable to 1600° Celsius, which is higher than any temperatures consumers would use their phones for. Additionally, sapphire glass is completely clear, so no matter what angle you look at your phone, you’ll be able to see through the glass to the display.
Why is sapphire glass not used in all smartphones?
Though sapphire glass seems like the perfect material for smartphone covers, it’s not used in all brands for several reasons. First, this material is costly to manufacture — that’s why you only see it in high-end watch brands instead of all watches. Even if consumers are willing to pay a lot more for sapphire glass, it has other problems, too.
Additionally, disposing of sapphire glass is difficult, and the high melting point of sapphire glass — 2030° Celsius — makes melting it down harder than standard glass. With so many new smartphones coming out in a variety of sizes, even reusing the sapphire glass faces from phones would be expensive because they would need re-machining to cut them down to the new size.
Sadly, the one aspect that makes sapphire glass desirable, also makes it more fragile. Though sapphire crystal resists scratches, it can still break easily if you drop your phone. You might still need a new display if your sapphire glass one shatters when your phone falls to the ground.
Sapphire glass on smartphones of the future
Though some smartphones use sapphire glass now, it’s only on specific models. If a scratch-proof phone that never needs a display cover sounds excellent to you, you might benefit from purchasing a sapphire glass smartphone. Regardless of your phone use, you’ll still benefit from sapphire glass’s continued use to protect the camera lens and other smaller parts of your phone.
This article was written by Megan Ray Nichols. If you enjoyed this article, please visit her website Schooled by Science.