Mjölnir
Thor’s hammer, worn as a pendant across the Viking world. Around a thousand examples survive, and one is even labelled in runes: this is the best-attested Norse symbol there is.
The drawing above shows one form of the symbol. Historical examples vary (sometimes considerably), and no single version should be treated as canonical.
Earliest attestation: 9th–11th century
The oldest surviving appearance we can actually point to.
Hammer-shaped pendants appear across Scandinavia and the Viking diaspora from the 9th to the 11th century, with roughly a thousand known examples. A pendant found at Købelev on Lolland, Denmark, carries a runic inscription reading hmar x is, "this is a hammer": the only find that names itself.
Historical use
Mjǫllnir is central to Old Norse mythology, where Thor uses it against the giants and to hallow. Hammer amulets are often read as a pagan response to the Christian cross, and moulds have been found that cast both hammers and crosses, which suggests the two coexisted commercially as well as religiously.
Modern use
The standard emblem of modern heathenry and Ásatrú. The clearest documented case of a state treating it as one is the United States, where the Department of Veterans Affairs added Mjölnir to the emblems permitted on government headstones in 2013, as emblem 55. Also heavily commercialised through Marvel’s Thor.
Common misconceptions
Claims about this symbol that circulate widely and do not hold up.
The Marvel hammer shape, a squared-off sledgehammer, is not the archaeological form. Viking-Age pendants are typically short-hafted with a broad, flat, often decorated head.
Sources
Full references on the sources page.