You’re reading this article on a screen, likely a phone but maybe a tablet. Covering that screen is an invisible piece of technology that you probably don’t think much about, but that piece of glass can trace its journey all the way back to the 1800s when a company called Corning set out to hack glass and extend its uses way beyond just windows.
This is the story of how Corning has stayed relevant and innovative, now going on 175 years, and how a particular call from Steve Jobs in 2007 massively changed the trajectory of this company that today has its glass on over 8 billion devices worldwide.
Corning started as a glassworks company in the 19th century
A material science company that revolutionized glass
Established in the 19th century in Corning, New York, Corning is a material science company that happens to use glass as its primary medium. Calling it a high-tech glass company undersells its impact. Corning developed materials that helped enable the electric light bulb, transformed cookware, and advanced fiber-optic communications. More recently, it created the nearly invisible technology protecting the smartphones we use every day: Gorilla Glass.
Apple users may know Corning’s glass as Ceramic Shield. Corning manufactures it in close collaboration with Apple, and the Ceramic Shield 2 used on the iPhone 17 includes an Apple-designed coating.
Our journey begins back in 1879 when Thomas Edison, inventor of the light bulb, was looking for a glass casing that could withstand the intense heat of his filament without shattering. Corning made a heat-resistant glass just for him, allowing Edison to commercialize his incandescent light bulb and quite literally change the course of humanity.
Later, in 1915, Corning developed Pyrex, the first heat-resistant cookware. They revolutionized how people bake and store food, allowing people to cook at high temperatures without fear of glass shattering, and in fact you probably have some Pyrex cookware in your kitchen right now.
But in 1998, Corning sold off Pyrex in order to focus on high-tech industrial applications for their glass, such as fiber optics.
From cookware to fiber optics
Corning literally helped lay the groundwork for the internet
Corning didn’t invent fiber optics (which allows for very fast internet, but is not always worth it), but it came up with an innovation that let fibers of glass transmit data over long distances at the speed of light. To do that, Corning intentionally “doped” the glass by introducing impurities like titanium in order to change how the light refracts inside the glass.
This single invention, made possible by Corning researchers, laid the groundwork for telecommunications and the internet itself because it allowed data to travel far distances without losing fidelity. What Corning did was create ultra-pure glass with such low signal loss (they hit 16–17 dB of light loss, beating the 20 dB threshold needed for reliable transmission) that light could travel long distances without fading.
But Corning had another innovation back in the 1960s that was at first deemed a failure that later provided the groundwork for a product you use every day.
A new invention intended for automobiles
Corning’s “Project Muscle” was a failure at first
Gorilla Glass isn’t exactly a new invention. It actually came from a 1960s technology Corning had put on the shelf because they lacked an application for it. The project was called Project Muscle, when Corning started experimenting with chemically-strengthened glass.
The target market for this super-glass in the 1960s was actually the automotive industry: Corning tried to sell this thinner but stronger glass to automakers. But Project Muscle failed — automotive companies didn’t want to pay extra for Corning’s fancy glass, preferring the cheaper, laminated glass that was already used. Corning did sell this 1960s glass — under the name Chemcor — for niche uses like car windshields, safety glasses, and pharmaceutical vials. But it never found a mass-market home, and by 1971 Corning put it on the back burner.
Little did they know that about 40 years later, they’d pick up where they left off with this revolutionary glass, but this time it was for an amazing new product out of Apple Computer.
In 2007, a call from Steve Jobs changed everything
Jobs needed help solving a major problem with a new device called iPhone
Forty years later, Steve Jobs went on stage to unveil the iPhone in January 2007. But what many don’t know is that the original iPhone prototype had a plastic screen, much like nearly all the PDAs and phones that came before it, since plastic is cheap and doesn’t shatter when dropped.
But there was a major problem with the iPhone prototype Steve Jobs carried in his pocket. Weeks before launch, with the ship date set, he pulled it out of his pocket and found the screen to be covered in scratches because of keys he had in his pocket coming into contact with the soft plastic screen.
Being obsessed with aesthetics and detail (after all, he was brilliant at seeing the future arc of technology), Steve Jobs knew the iPhone couldn’t ship with a plastic screen that could scratch easily.
But what he wanted—a durable but thin glass that was highly touch-sensitive that could be made in massive volumes (in just a few months when the iPhone started shipping)—didn’t exist yet. So Jobs called the glass experts at Corning, who dusted off the chemistry behind their shelved 1960s project — the glass they’d once sold as Chemcor — and adapted it for the iPhone under a new name: Gorilla Glass. Steve Jobs needed a miracle with just six months until the first iPhone would ship, and Corning was up to the task, though they were hesitant at first. It’s well documented that Corning was nervous about the tight timeline, and Jobs told the Corning CEO Wendell Weeks “Don’t be afraid. You can do this”.
The science of Gorilla Glass
What’s the secret behind this magical material?
I made this video in 2011 to show the durability of the original Gorilla Glass when I was fascinated by this technology. Since then, we’ve seen additional generations of Gorilla Glass, such as Gorilla Glass Victus 2 on the latest Samsung phones (which is made like a tank, offering drop protection from face-down drops on concrete up to 1 meter, and up to 2 meters on asphalt surfaces like those in parking lots, and yet it’s ultra thin at just 0.4mm to 1.2mm thick, compared to 1.5mm on the first generation Gorilla Glass).
The key is when they take a special formulation of glass, called alkali aluminosilicate glass, which incorporates aluminum and silicon. Corning makes Gorilla Glass strong by stuffing larger ions into a space originally occupied by smaller ions when they take this special glass and submerge it in a bath of molten alkaline potassium salt.
This process creates a dense surface layer under high compressive stress that acts like a shield against cracks. The net result of all of this engineering is that the glass on your phone is essentially “fighting the break before it happens”. This is known as residual compressive stress, and it works such that if you drop your phone, the compressive stress on the surface fights against the tension of the impact and stops a surface scratch from turning into something worse.
The future of glass innovation
What’s next for Gorilla Glass? Corning is shifting their focus to something called lifetime fatigue resistance, which recognizes that a phone must not only survive one drop, but multiple drops, since most people are a little careless with their phones. By integrating microscopic nanocrystals inside the glass matrix, future versions of Gorilla Glass will have even greater strength, yet be even thinner.