alfsaga:

Occult Knowledge and Symbols - Galdrastafir (ancient Icelandic magic symbols). Icelandic magical staves (sigils) are symbols credited with magical effect preserved in various grimoires dating from the 17th century and later.

According to the Museum of Icelandic Sorcery and Witchcraft, the effects credited to most of the staves were very relevant to the average Icelanders of the time, who were mostly subsistence farmers and had to deal with harsh climatic conditions.