Tin silicate-borate-oxide equilibria in skarns and greisens; the system cao-sno₂-sio₂-H₂O-B₂O₃-CO₂-F₂O_{- 1}

This study is aimed at explaining why tin minerals other than cassiterite are not more common. It demonstrates that, in the presence of quartz, fluorite, calcite, and other gangue minerals typical of skarn and greisen-type tin deposits, cassiterite is the only stable tin mineral if conditions are relatively acidic and low in temperature. Such conditions appear typical of greisens and the late stages of skarns. Other nonsulfide tin minerals, such as the silicates malayaite and stokesite, and the borate nordenskioeldine, are stable only under unusual conditions. Refs.