(Picture: HBO)The White Walkers are now closing in on Winterfell, and Game of Thrones fans are preparing for the biggest battle in the show’s history.
It is set to see the Night King’s army of the dead close in an attempt to destroy everyone in their way as well as kill Bran Stark.
In the lead-up to the battle Jon Snow has been encouraging everyone to mine dragonglass and forge it into weapons, including blades and arrows.
He even made the trip to Dragonstone with Daenerys, as it is a location that is known for have a lot of the material in its caves.
Here is everything that you need to know about dragonglass and why it is a weakness of the white walkers.
(Picture: HBO)What is dragonglass?
Dragonlass is the word used in Game of Thrones to describe the substance known as obsidian.
Obsidian exists on earth and is a glass-like rock, formed of volcanic lava that has solidified.
It is when the lava that has left a volcano cools down quickly without much crystallisation.
Dragonstone is known as an area that has a lot of dragonglass, and it was mined by Jon Snow, Danaerys Targaryen and their supporters in season seven as they prepared to face the White Walkers.
Why can dragonglass kill White Walkers?
Dragonglass was an important tool for the Children of the Forest, who were living in Westeros when the First Men had arrived, several thousands of years before the current Game of Thrones events.
They used it a lot as weapons, particularly when fighting against the first men.
During season six Bran Stark has a vision that shows the Children of the Forest performing a ceremony and using a dragonglass dagger to turn a man into a White Walker.
(Picture: HBO)The fact that the White Walkers were initially made by dragonglass is likely why it is one of their main weaknesses, along with fire.
It’s use as a weapon against the White Walkers was first discovered in season three when Samwell Tarly manages to use it to kill one and protect Gilly’s baby.
Valyrian steel is another material that is known to kill White Walkers after Jon Snow successfully used his sword to take down a White Walker at Hardhome.
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