text: Mineral symbols (text abbreviations) are used to abbreviate mineral groups, subgroups, and species, just as lettered symbols are used for the chemical elements.
  The first set of commonly used mineral symbols was published in 1983 and covered the common rock-forming minerals using 192 two- or three-lettered symbols. These type of symbols are  referred to as Kretz symbols. More extensive lists were subsequently made available in the form of publications or posted on journal webpages.