Rammelsbergite is a rare mineral that is named after the Rammelsberg mine in Germany, where it was first discovered. This mineral belongs to the arsenic sulfide group and has the chemical formula NiAs2. There are some synonyms for the word "rammelsbergite." These include nickel arsenide, nickel diarsenide, and nickel sulfarsenide. These terms are used to describe minerals that have a similar chemical composition and crystal structure to rammelsbergite. Nickel arsenide and nickel diarsenide are self-explanatory synonyms as they refer to the presence of either two or one arsenic atoms in the mineral. Nickel sulfarsenide is also a reference to the mineral's arsenic and sulfur content. In summary, rammelsbergite is a rare mineral that has some synonyms like nickel arsenide, nickel diarsenide or nickel sulfarsenide.