Journal of the Chemical Society Abstracts
M i n e r a1 o gi c a Z C h e m i s t r y. Hyacinth (Quartz) in Gypsum, near Jena. By E. ZSCHCMMER (Tsch. Min. Mitth., 1896, 15, 457-465) .-Small, red, doubly-terminated crystals of quartz occur with small crystals of dolomite in gypsum bands in the Trias beds near Jena ; they enclose gypsum, and probably also anhydrite. Experiments show that silica is fairly Chili, 1895, 5, 87--88).-The mineral is black and amorphous ; streak, black; fracture, conchoidal; sp. gr., 3.39; H = 3.5. With
... 3.5. With hydrochloric acid it gives off chlorine ; over snlphnric acid some water is lost. Analysis gave fI20 H2O Co. Cu. Si02. Fe,03. (hygroscopic). (combined). 0 [diff.]. 46-76 12-65 1.76 0.29 4.92 1408 119.541 This agrees with Cn0,2Co0,Co203 + 4H20. The exact locality is The mineral is not known, but is probably in the north of Chili. named Schzdxenite, after J. Schnlze, in whose collection it was found. L. J. S. Formation of Tin Veins. By FERDINAND GAUTIER (Actes SOC. Sci., Chili, 1895, 5 , 82-84).-From the non-occurrence of minerals containing fluorine in the cassiterite veins of some districts of Bolivia, the author supposes the tin dioxide to have been formed by the interaction of water vapoilr and tin chloride. The cassiterite of another Bolivian locality shows impressions oE quartz crystals ; this seems to imply that there has here been interaction between water vapour and tin fluoride, the quartz being acted on by the hydrogen fluoride formed, and removed 8s silicon fluoride ; minerals containing fluorine are, however, in this case also absent. 11. J. S.