A system of abbreviations for rock-forming minerals was first proposed by Kretz (1983), which has since been widely adopted. Over the years, several revisions have been made, including by Spear (1993), Holland and Powell (1998), the Mineralogical Association of Canada, and Siivola and Schmid (2007). The current list contains 371 abbreviations, including many new entries resulting from research in high- and ultrahigh-pressure metamorphic regions, the inclusion of Mg and Fe end-members, extraterrestrial samples, and the increased relevance of accessory minerals in petrology. Two main systems are currently in use: Kretz (1983) with modifications and Holland and Powell (1998). The Kretz system uses 2–3 letters with uppercase for minerals and lowercase for components, while the Holland and Powell system uses 1–5 letters with all lowercase. Both systems have some overlapping abbreviations but differ in symbols for the same minerals. The selection of minerals is subjective, but the authors have aimed to be inclusive, including some minerals with questionable status. The list also includes some hypothetical and synthetic phases, as well as an abbreviation for "liquid" (Liq). Mineral groups and descriptive terms are also included. Abbreviations are chosen to make mineral identities clear and unambiguous. The updated list of abbreviations follows specific rules, such as capitalizing the first letter, using letters from the mineral name, and avoiding conflicts with element abbreviations. The authors acknowledge Marc Hirschmann and Howard Day for their input. References include Kretz (1983), Holland and Powell (1998), Siivola and Schmid (2007), and Spear (1993). Table 1 provides the updated list of abbreviations.A system of abbreviations for rock-forming minerals was first proposed by Kretz (1983), which has since been widely adopted. Over the years, several revisions have been made, including by Spear (1993), Holland and Powell (1998), the Mineralogical Association of Canada, and Siivola and Schmid (2007). The current list contains 371 abbreviations, including many new entries resulting from research in high- and ultrahigh-pressure metamorphic regions, the inclusion of Mg and Fe end-members, extraterrestrial samples, and the increased relevance of accessory minerals in petrology. Two main systems are currently in use: Kretz (1983) with modifications and Holland and Powell (1998). The Kretz system uses 2–3 letters with uppercase for minerals and lowercase for components, while the Holland and Powell system uses 1–5 letters with all lowercase. Both systems have some overlapping abbreviations but differ in symbols for the same minerals. The selection of minerals is subjective, but the authors have aimed to be inclusive, including some minerals with questionable status. The list also includes some hypothetical and synthetic phases, as well as an abbreviation for "liquid" (Liq). Mineral groups and descriptive terms are also included. Abbreviations are chosen to make mineral identities clear and unambiguous. The updated list of abbreviations follows specific rules, such as capitalizing the first letter, using letters from the mineral name, and avoiding conflicts with element abbreviations. The authors acknowledge Marc Hirschmann and Howard Day for their input. References include Kretz (1983), Holland and Powell (1998), Siivola and Schmid (2007), and Spear (1993). Table 1 provides the updated list of abbreviations.