Color, iron-black to steel-gray. Generally resembles pyrolusite, but is distinguished from it by its superior hardness. It frequently contains BaO and Li2O. It behaves before the Bp. like pyrolusite.
Wad (Bog Manganese).—This mineral is essentially MnO2, MnO, and H2O, with small quantities of Fe2O3, Al2O3, BaO, SiO2, etc., associated with it.
H = 0.5-6.0, G = 3.0-4.2. Color, dull black. Heated in an ignition tube yields water in abundance, otherwise it behaves like pyrolusite.
Ores of Mercury
Native Mercury, Hg.—G = 13.5-13.6. Color, silver-white. Is liquid at all ordinary temperatures. Heated in an ignition tube is volatilized, the vapors condensing in the upper end of tube to small metallic globules of Hg. Before the Bp. on Ch. it is volatilized. Frequently contains Ag.
Cinnabar, HgS2, Hg . 86, S . 14.—
H = 2.0-2.5, G = 8.0-8.2.
Color, scarlet-red to brick-red. Lustre, non-metallic. When pulverized yields a powder of vermilion-red color. Heated in an ignition tube it volatilizes, yielding a black sublimate, which by friction becomes red. Before the Bp. on Ch. it is wholly volatilized. Heated in an ignition tube with Na2CO3 metallic mercury sublimes, condensing in the upper portion of the tube in minute globules.
Ores of Nickel
Millerite, NiS, Ni . 64.4, S . 35.6.—