Northblade is Garnet Tyler's weapon of choice. It is a Dust-Empowered Collapsible Saber (DECS) that Garnet has had since he was adopted by the Tyler family.
Northblade is a saber with the blade being a dark gray, with the handle being a darker grey with red highlights. The handle has a compartment where he can insert different types of Dust for different effects. Garnet wears a holster on his waist to hold Northblade.
Northblade has been with Garnet since he was adopted by the Tyler family. Apparently, Garnet had Northblade was he was found.