[Motorola Droid RAZR] garlick2:
Gorilla glass comes in standard thicknesses of .3mm, .7mm, 1.3mm & 1.8mm. There are larger thicknesses, but for consumer grade cell phone applications, they are not relevant, as thicker is not better when it comes to phones.

Each of these sizes has a very specific spec for the break stress aperture that the glass can withstand, but that doesn't apply fully to this phone, as there is also bond material that's used in between the glass and the AMOLED substrate.

Typically this bond material will add tensile strength (basically extra support to reduce flexing) to the display and the glass that's bonded to it.

What doesn't help, is that Motorola used a UV dry bond process to apply the glass to the LCD.

There are two different types of material that can be used for this process, optical silicone (which doesn't cure to hard state, imagine a tacky gel) or a Dry material (something that hardens completely, like a piece of plexiglass).

The optical silicone allows more flexibility of both the display & the glass that's bonded to it, which helps when you have non-uniform pressure applied to the display.

With dry bond material, depending if the pressure is equal across the top surface, or if it's applied in specific areas, you can see breaking actually increase because the material below the surface isn't flexible, and actually causes more pressure in non-uniform ways. So while you may only have 100 PSI (pounds per square inch) in one area, you'll actually multiply to 150-200 PSI in another area flexing the opposite direction.

I know your @$$ is not flat, so I would assume pressure was put non-uniformly across the phone. This is actually worse than if you took a car and drove over the phone, as there would actually be more uniform pressure across the front surface, than there would be in a roller coaster between your butt and the seat.

Still, this particular phone is so thin, I can't see Motorola going with anything larger than .7mm substrates on the Gorilla Glass. Possibly even the .3mm in this application, as every tenth of a millimeter counts in a phone THIS thin.

At that size, the amount of pressure guaranteed by Corning is actually less than 20 pounds dropped at around 5', which equals out to about 300 PSI, which as someone so eloquently already explained, you were probably well above this level at around 450-600 PSI during movement of the rollercoaster. Taking into account the dry bond material, you could have had forces up to 800-1000 PSI applied in opposite direction on the materials, based on force being applied in a non-uniform manner.

So the Gorilla Glass, while not living up to the standard of 3-5 G's, it probably fared quite a bit better than a non-gorilla glass substrate. So this definitely is not a corning issue.

On the comment about the difference between this and the DX & DX2, both those phones used a 1.3mm Gorilla Glass substrate (I know because I took one of my friend's dead phones apart and looked). So this will have a substantially higher shatter point.

Also, Gorilla Glass, while scratch resistant & really cool to talk about, actually does shatter easier than most believe. With Ion strengthened glass like this, when you strengthen anything, it becomes more susceptible to shattering, rather than chipping or scratching. So while it's stronger, and takes more force to shatter, it's more likely to shatter than it would to just chip or scratch. So rather than it chipping or scratching when you apply major force, you're more likely to destroy the whole piece of glass at first breakage, rather than have just a piece come off. So there are some trade offs to having a "scratch proof" front surface.