New Almaden hydrothermal deposition of cinnabar from deep within the earth is found in a gangue of silica-carbonate rock formed locally by hydrothermal alteration of serpentine. The Guadalupe mine produced about 10% as much mercury as the New Almaden. There are several smaller mines in the mining district, but their ore production was not significant. The only significant quicksilver ore is cinnabar; other sulfides are present in small quantities. Mining, other than a single placer deposit of cinnabar, was underground. There is a high probability of undiscovered high-grade ore which could be found and exploited using modern techniques. Mining operations resulted in
Metal ammine complex is ammonia (pK ~ 33). For highly cationic complexes such as [Pt(NH)], the conjugate base can be obtained. The deprotonation of cobalt(III) ammine-halide complexes, e.g. [CoCl(NH)] labilises the Co-Cl bond, according to the Sn1CB mechanism. Metal ammine complexes find many uses. Cisplatin (PtCl(NH)) is a coordination compound containing two chloro and two ammine ligands. This is a drug used in treating cancer. Many other amine complexes of the platinum group metals have been evaluated for this application. In the separation of the individual platinum metals from their ore, several schemes rely on the precipitation of [RhCl(NH)]Cl. In some separation schemes,