Geigerite is a rare mineral that belongs to the class of arsenates. It is notable for its unique deep green color and its crystal structure. While there aren't many synonyms for geigerite, it can be referred to as arsenic-containing copper sulfate or arsenate. Another similar mineral with a similar green color is olivenite, which is also an arsenate mineral. Other related minerals include phosphohedyphane, erythrite, and parnauite, all of which are arsenate minerals, and share some physical and chemical properties with geigerite. Despite its scarcity, geigerite is prized by collectors for its unique characteristics.