Mineral. Glance cobalt Formula. CoS^{2} + CoAs. Behavior (1) in glass-bulb. -- (2) in open tube. As the preceding, but gives off more SO^{2}. (3) on charcoal. Gives off S and As, and fuses to a magnetic bead. Colors flame blue. (4) in forceps. -- (5) in borax. Gives a cobalt and slight iron reaction when treated as the preceding minerals. (6) in mic. salt. As in borax. (7) with carb. soda. Gives a sulphur reaction of silver. (8) Special reactions. As the preceding. * * * * * Mineral. Nickel glance Formula. NiS^{2} + NiAs. Behavior (1) in glass-bulb. Decrepitates and gives an orange colored sublimate of AsS^{2}. (2) in open tube. As the preceding. (3) on charcoal. As the preceding. (4) in forceps. -- (5) in borax. As copper nickel. (6) in mic. salt. Gives the nickel reaction occasionally somewhat obscured by cobalt. (7) with carb. soda. As the preceding. (8) Special reactions. As copper nickel. * * * * * Mineral. Ulmannite Formula. NiS^{2} + Ni(AsSb)^{2}. Behavior (1) in glass-bulb. Gives a slight white sublimate of SbO^{3} and more or less AsS^{3}. (2) in open tube. Gives off thick fumes of SbO^{3} and SbO^{5} with AsO^{3} and SO^{2}. (3) on charcoal. As glance cobalt, but accompanied by dense fumes of SbO^{3}. (4) in forceps. -- (5) in borax. As copper nickel. (6) in mic. salt. As the preceding. (7) with carb. soda. As the preceding. (8) Special reactions. As copper nickel generally, but arsenic is not always present. * * * * * Mineral. Cobalt pyrites Formula. ([,Co][,Ni][,Fe]) ([,,,Co=][,,,Ni=][,,,Fe=]). Behavior (1) in glass-bulb. When strongly heated gives off sulphur and becomes brown. (2) in open tube. Gives off much SO^{2} and a small quantity of AsO^{3}. (3) on charcoal. In the reducing flame small fragments fuse with the evolution of sulphur to a magnetic bead having a bronze colored fracture. (4) in forceps. -- (5) in borax. In the oxidizing flame on charcoal gives a violet colored glass. In the reducing flame the nickel is reduced and may collected in a gold bead. When the nickel is removed, the glass exhibits a slight iron reaction while warm.