Two fragments of the neck of a "boat axe" from the late Neolithic period (Stone Age). The fragments are from more than 1000 years before the Viking Age but were found together with other Viking objects deposited in a ditch between two buildings in Svarta Jorden, Birka. The fragments were probably thought by the person or people who deposited them during the Viking Age to be magic thunderstones. Svarta Jorden, Birka, Adelsö Parish, Uppland.
