Updated 02 May 2014 to reflect Samsung's reply in post #25. Further to a thread here... http://androidforums.com/samsung-galaxy-s4/842667-samsung-galaxy-s4-problems.html which, strangely I thought, mentioned that AT&T charged extra for installing Gorilla Glass 3 onto their version of the Galaxy S4, I did some digging and came across this thread... No Gorilla Glass on ATT S4? - xda-developers ... which not only confirms this in post #1... "It's not Samsung it's ATT. We have to pay extra for Gorilla Glass and we did not."She went on to explain how they've gotten tons of claims regarding easily broken screens on the S4 and so they were recently informed that the lack of Gorilla Glass is the culprit." Furthermore, in post #24, it goes on to say that... "You can call Samsung Technical Support and ask them, I did, and they told me the only version that has gorilla glass is the international version." Checking this out further, I went to the Corning Gorilla Glass 3 website for the Samsung Galaxy S4, (Samsung GALAXY S4 | Products | CORNING® GORILLA® GLASS ), and sure enough, there is, in the small print... "Select device manufacturers have not been willing to provide Gorilla Glass model verification. In those cases, please ask the manufacturer directly or contact Corning here and we will do our best to help you." So, I contacted Samsung UK, Technical Support, ( Helpline & Contact | Samsung UK ), who assured me that the International models, GT-i9505, (quad core), and GT-i9500, (octa core), all had the toughened Gorilla Glass 3 but that I would need to contact the individual carriers for the minority variants. So, if you do not own an International model and want to know if your variant is protected by Corning's Gorilla Glass, you will need to contact your carrier or Corning Gorilla Glass. To locate your model version, go to... Settings > More > About device > Model number. The actual pathway my vary depending on your model. Alternatively, it should say on the white sticker underneath the battery. This will give you the model of Samsung Galaxy S4 that you have. Galaxy S4 Model number (I will update this post whenever I receive confirmation on a particular model) International GT-i9505 Yes Confirmed by Samsung. Corning Gorilla Glass 3 AT&T Google Edition (see above) GT-i9505G Yes Confirmed by Samsung. Corning Gorilla Glass 3 International GT-i9500 Yes Confirmed by Samsung. Corning Gorilla Glass 3 International GT-i9506 Yes Confirmed by Samsung. Corning Gorilla Glass 3 S. Korea SHV-E300K/L/S No S. Korea SHV-E330K/L/S No Japan NTT SGH-N045 No China Mobile GT-i9508 No China Telecom SCH-i959 Yes Confirmed by Samsung. Corning Gorilla Glass 1 China Unicom GT-i9502 Yes Confirmed by Samsung. Corning Gorilla Glass 3 AT&T SGH-i337 No T-Mobile/Metro U.S.A. SGH-M919 No Verizon SCH-i545 Yes Appears to be confirmed on Verizon's own website. Sprint SPH-L720 Yes Confirmed by Samsung. Corning Gorilla Glass 3 Cricket SCH-R970C No Confirmed by Samsung C-Spire SCH-R970X No US Cellular SCH-R970 No Canada (various) SGH-M919V No Confirmed by Samsung Canada/Mexico (various) SGH-i337M No Active GT-i9295 Yes Confirmed by Samsung. Corning Gorilla Glass 2 This might explain why we are seeing posts about cracked and damaged screens from some models in particular.