It's not dragon glass. It's Valyrian steel. Jeor Mormont (Jorah's father and the old Lord Commander) gave it to Jon in season 1. Valyrian steel weapons were forged in Valyria with spells and dragonfire, that's why it kills white walkers. It's lighter, stronger and much sharper than a normal sword. Valyria was a great empire ruled by men who tamed dragons and great magic. It fell into chaos long ago and now only the ruins exist, that's where the Targaryens came from. Also, valyrian steel swords are very rare because they can't be made anymore, people who have them pass them down through their family. Because Jorah fled Westeros, Jeor gave it to Jon after he defeated the Wight that tried to kill him.

Doesn't Jamie have a valyrian sword as well?

Such an amazing episode! I always thought the bearded guy was the one in command then I see him shatter... Was craziness!!

Jamie's sword Oathkeeper is in the hands of Brienne at the moment, He gave it to her.

One thing that doesn't make sense about this ep, from both the books and tv show standpoint, how come they didn't have to kill the wights with fire? They made it clear in both you need fire to stop a Wight.

They are still subject to the laws of physics. Remember the hand in the jar they brought to King's Landing stopped moving after awhile. In this battle, they could rip bodies apart with normal weapons and the parts would just keep twitching.

But they aren't.. they secured that hand and the magic probably evaporated after some time. In the battle of the fist of the first men, there are limbs coming after them, a bear gets his head cleaved off and in return mauls his attackers head right off. Even that wight in the show keeps crawling after Sam until Jeor shows up and puts him to the torch. Necromancy doesn't abide by the laws of physics, there's no blood pumping in them and they don't breath.

"magic probably evaporated after some time" is a new interpretation I've never been exposed to.

If you cut a wight in half, each half will keep moving. If you keep cutting each half in half, eventually you make then into small enough pieces that they aren't a threat anymore. That's what I think they were doing in this battle tonight.

When you get stomped on by a giant and crushed like a bug on a windshield, it doesn't matter how magic you are. You're not gonna move lol

Best episode so far this season.

Great battle scenes, and wonderful to finally see that what book readers have theorised for a while (dragonsteel = valyrian steel) is confirmed. Yay.

Might also be the first Dany scene this season that I approve of.

I hope ep 9/10 can live up to this one!