Antimony discontinued. Antimony is resistant to attack by acids. Four allotropes of antimony are known: a stable metallic form and three metastable forms (explosive, black and yellow). Elemental antimony is a brittle, silver-white shiny metalloid. When slowly cooled, molten antimony crystallizes in a trigonal cell, isomorphic with the gray allotrope of arsenic. A rare explosive form of antimony can be formed from the electrolysis of antimony trichloride. When scratched with a sharp implement, an exothermic reaction occurs and white fumes are given off as metallic antimony forms; when rubbed with a pestle in a mortar, a strong detonation occurs. Black antimony
Germanium disulfide Germanium disulfide Germanium disulfide or Germanium(IV) sulfide is the inorganic compound with the formula GeS. It is a white high-melting crystalline solid. The compound is a 3-dimensional polymer, in contrast to silicon disulfide, which is a one-dimensional polymer. The Ge-S distance is 2.19 Å. Germanium disulfide was the first germanium compound found by Clemens Winkler, during the analysis of argyrodite. The fact that germanium sulfide does not dissolve in aqueous acid made it possible for Winkler to isolate the new element. Germanium disulfide is created by reacting hydrogen sulfide with germanium tetrachloride in a concentrated hydrochloric acid solution. Natural GeS