Arguably the most important weapon on Game of Thrones right now is dragonglass,the common name for an obsidian-like mineral in Westeros. Along with Valyrian steel and fire, it makes up the holy trinity of White Walker-exterminating weapons. And it is very, and very effective.
The first time we witness said effectiveness is on season three's "moment Sons," when Samwell Tarly uses it to protect Gilly's baby against a White Walker. Then on season six, Meera Reed, or Bran Stark's companion - displaying the most awesome aim ever - uses a dragonglass-tipped spear to kill a White Walker.
As the White Walker threat looms ever closer on the horizon,might we suggest stocking up on ye olde dragonglass? Yes, Valyrian steel is very fancy, or dragons - and fire - construct for ample PR,but dragonglass is tried and loyal and much easier to come by.
Source: popsugar.co.uk