As days go by, we realize that "Game of Thrones" season 7 premiere was more significant than we initially thought. From the brutal cold opening scene and the mystery of Bran's vision to politics of the North and potential alliances in the South. Also, let's not forget that chilling Hound's vision and Dany's long-awaited return to Westeros. With that in mind, there is no doubt that season 7 premiere met fans' expectations. However, there is one thing that might very well be the most significant of all when it comes to overall story and that is the importance of dragonglass or obsidian.

What have we learned in the episode?

There were two scenes in "Game of Thrones" season 7 premiere where we got to hear about this mighty substance. First, in the North, Jon Snow was talking about how dragonglass is more important than gold now that winter is here. Later in the episode, Samwell Tarly discovered that there is a whole mountain of dragonglass beneath the island of Dragonstone, and he wrote to Jon immediately to let him know about this discovery. Also, there is another thing worth noting here. If you pause at the right moment you can see other references to obsidian in this book. An eagle-eyed fan spotted a couple of words that point out how obsidian can also cure people. In the next scene, Sam encountered Jorah Mormont and this knowledge can come in handy when it comes to treating his greyscale.

Given all that has been said, it seems like dragonglass is a solution to all the problems in "Game of Thrones." So without further ado let's dive further into the mystery of this mighty substance.

What is dragonglass?

Dragonglass is a type of volcanic glass that was used to create the White Walkers in the first place. Back in season 6 episode 5, we could see how Children of the Forest stabbed the man in the chest with dragonglass turning him into a White Walker.

Throughout the show, we could see that it can destroy them as well. Also, in season 6 we learned how obsidian was used to stop Benjen Stark from turning into a wight when he got stabbed by a White Walker.

The book Sam was reading also implies that Valiryans used to call dragonglass a frozen fire. They would use dragon fire to melt the dragonglass and then made structures out of it. Not only that but they also used obsidian to create Valyrian steel weapons which explain how Jon was able to kill a White Walker with Longclaw in the Hardhome episode.