Yes this is Dragonglass referred to in HBO's hit Game of Thrones.
Black Obsidian Arrowheads come from powerful ancient tradition. Native Americans fashioned arrowheads like these to use as spears and weapons and also wore them as luck talismans into battle.
Black obsidian is a protective and grounding stone. It opens the root chakra and casts energy that mirrors your soul. It is also a powerful stone for releasing, mourning, and letting go. You can use this beautiful and symbolic piece as a reminder that transition is natural, necessary, and sacred, keeping it with you through times of trial or grief.