Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/406

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388 MINERALOGY 109. MANGANITE, Mn 2 3 , H 2 . Right prismatic, sometimes henrihedric ; oP ( J7) 99 40. Crystals prismatic (figs. 298 to 300); vertically striated; also columnar or fibrous. Hemitropes com mon. Cl. brachydiagonal, perfect ; brittle. H. -3 5 to 4; G. =4 3 to 4 4. Opaque; metallic lustre. Steel-grey to iron-black ; streak brown. B.B. infusible. Sol. in warm h. acid. C.c. : peroxide of manganese 89 "9, water 101. Grandholm (Aberdeenshire), Cork, Upton Pyne (Exeter), Churchbill (Somerset), Warwickshire, Ihlefeld, Thuringia, Norway, Sweden, Nova Scotia. Fig. 298. dd Fig. 299 (sp. 109). 110. LIMONITE, 2Fe 2 3 + 3H 2 0. Fibrous, botryoidal, and stalactitic, some- v - -mm times earthy. H.=4 5 to 5 -5; G.-3 4 to 3 95. Opaque ; lustre silky, glimmering, or dull. Brown, yellow ish and blackish brown, often black on surface ; streak ochre- yellow. In closed tube yields water and becomes red. B.B. in inner flame becomes magnetic, fusing to a glass. C. c. : peroxide of iron 85 6, water 14 4. Sandlodge (Shetland), Hoy (Orkney), Clifton, Bristol, Cornwall, Harz, Thuringia, Nassau, Styria, Carin- thia, Siberia, United States. 111. XANTHOSIDERITE, Fe 2 3 , 2H 2 0. Fibrous, stellate, also as an ochre. H. =2 5. Silky or greasy, pitch-like or earthy. In needles, golden-yellow or brown-red; as an ochre, yellow, red, or brown ; streak ochre-yellow. B.B. like limonite. C,c.: peroxide of iron 81 6, water 18 : 4. Hoy(Orkney), Achavarasdale, Kilbride, Wicklow, Ilmenau, Goslar, and Elbingerode in the Harz. 112. BEAVXITE, (3A1 2 3 , Fe 2 3 ), 2H 2 0. Oolitic, concretionary, disseminated ; also earthy and clay-like. G. =2 55. White, grey, ochre-yellow, brown, and red. C.c.: alumina 50 4, peroxide of iron 26 1, water 23 5. From Beaux (or Baux) near Aries, and elsewhere in France. In grains in compact limestone. Pure varieties used for manufacture of aluminium. 113. ELIASITE, U 2 3 + 2H 2 0. Amorphous masses; resin-like. H. = 3 5 to 4 "5; G. =4 to 5. Reddish brown to black ; streak wax-yellow to olive-green. C. c. : 68 5 per cent, sesquioxide of uranium. 10 of water, with impurities. Elias mine (near Joachimsthal). 114. BRUCITE, MgO,H 2 0. Rhornbohedral ; R 82 22 ; also foliated and botryoidal columnar. Cl. basal, perfect ; sectile ; lamina flexible. H. =2 ; G. =2 3 to 2 4. Translucent, pearly. Colourless. B.B. infusible. Easily soluble in acids. C.c. : 69 magnesia, 31 water. Nemalite is a fibrous variety with silky lustre. Swinaness and Quin Gio in Unst, Beresovsk in the Urals, Hoboken, New Jersey, Texas, Pennsylvania. 115. PYROCHUOITE, MnO, H 2 . Foliated. H. =2 5. Pearly, white, but changing through bronze to black. Flesh-red by transmitted light. In matrass becomes verdigris-green, finally black, yielding water. Sol. in h. acid. C.c. : protoxide of manganese 79 8, water 20 2. In veins in mag netite at Paisberg in Sweden. 116. GIBBSITE (Hydrarfjillite}, A1 2 3 , 3H 2 . Hexagonal. C.c. : 65 5 alumina, 34 5 water. The crystals are from Zlatoust in the Urals ; stalactites from Richmond in Massachu setts and Villa Rica in Brazil. 117. LIMXITE, Fe 2 3 , 311,0. Massive in stalactites, also as a yellow ochre. Like limonite, but pitchy lustre. C.c.: peroxide of iron 74 8, water 25 2. Leadhills, Botallack (Cornwall), Novgorod (Russia). 118. HYDKOTALCITE, A1 2 3 , 311,0 + 6MgO, H 2 + 6H 2 0. Hexagonal. Cl. bas.il, foliated, and somewhat fibrous. H. =2 ; G. =2 04. White, pearly. Greasy to the touch. Translucent. C.c. : alumina 16 8, magnesia 39 2, water 44. Zlatoust, Urals; S:iarum, Norway ; New York. 119. PYROATJRITE, Fe 2 3 , 3H 2 + 6MgO, H 2 + 6H 2 0. Hexagonal ; tables and scaly coatings. Lustre pearly to sub- metallic. Colour white to gold-yellow. Translucent. RB. in fusible, yields water. Sol. in h. acid. C.c. : peroxide of iron 23 9, magnesia 35 8, water 40 3. Haaf Grunay in Shetland, L&ng- ban in Wermland. 120. GUMMITE, U 2 3 , 3H 2 0. In rounded lumps, resembling gum. H. =2 5 to 3 ; G. =3 9 to 4 2. Lustre greasy. Reddish yellow to yellowish brown. C.c. : 72 per cent, sesquioxide of uranium water 1475, with impurities. Juhann-Georgenstadt. 121. PSILOMELANE, (BaO, MnO) Mn0 2 + 3H 2 0, Mn0 2 + 3H 2 0. Massive and botryoidal ; fracture conchoidal. H. =5 5 to 6 ; G. = 4-1 to 4 3. Bluish black. B.B. infusible. About 80 per cent, of oxide of manganese, with baryta, potash, and water. Hoy (Orkney), Leadhills, Cornwall, Devon, Schneeberg, Ilmenau, Vermont in France. Wad is similar, but sometimes soft and light. Lead- hills, Cornwall, HaTz, France. 122. CHALCOPHANITE, MnOZnO + 2Mn0 2 + 2H 2 0. Hexagonal. R:R11430 . Cl. basal. H. =2 5; G. =3 91. Metallic lustre. Blue-black ; streak brown, dull. Opaque ; flexible. C.c. : manganese binoxide 59 "94, protoxide 6 "6, zinc oxide 217, water 11 6. Sterling Hill (New Jersey). OXIDES OF NON-METALS. 1. OXIDES OF ARSENIC- ANTIMONY FAMILY (TEROXIDES). 123. ARSENOLITE, As0 3 . Cubic; in octahedra; also botryoidal, stalactitic. H. =1 5; G. = 3 7. Lustre vitreous. AVhite; streak pale yellow. Translucent. Sublimes inclosed tube, condensing in brilliant octahedra. C.c.: arsenic 7576, oxygen 24 24. Cornwall, Andreasberg, Joachimsthal. Kapnik (Hungary), Nevada, California. 124. SENARMONTITE, Sb0 3 . Cubic; in octahedrons. Cl. octahedral, also massive granular. H. =2 to 2 5; G. =5 22 to 5 3. Transparent; adamantine. White or grey. B.B. in inner flame fuses and colours the flame greenish blue. Sol. in h. acid. C.c. : antimony 83 56, oxygen 16 44. Endellion in Cornwall, Constantine in Algeria, Malaczka in Hungary. 125. VALENTINEITE, Sb0 3 . Right prismatic; ooP137. Cl. ooP, perfect. H. =2 5 to 3; G. =5 5 to 5 "6. Translucent; adamantine to pearly. Yellowish white, brown- grey; streak white. Other properties and composition like senar- montite. Glendinning (Dumfriesshire), Przibram, Braunsdorf (Saxony), Harz, Hungary, Allemout (Dauphine), Siberia, 126. BISMITE, Bi0 3 . Massive, earthy. G. =4 36. Grey, yellow, green. C.c. : bismuth 89 65, oxygen 10 35. St Agnes (Cornwall), Schneeberg, Siberia. 127. MOLYBDITE, Mo0 3 . Right prismatic; oP 136 48 . In capillary crystals, also powdery. H. =1 to 2; G. =4 5. Straw-yellow to yellowish white. C.c.: molybdenum 6571, oxygen 34 29. With molybdenite at many of its localities. 128. TUNGSTITE, W0 3 . Earthy. Soft yellow or yellowish green. Sol. in alkalies. C.c. : tungsten 79 3, oxygen 207. Cumberland and Cornwall, Monroe in Connecticut. 129. CERVANTITE, Sb0 3 + Sb0 5 . Right prismatic. Acicular, generally earthy. H. = 4 to 5; G. = 4 1. Isabel-yellow, reddish white. B.B. on charcoal reduced; un altered per se. Sol. in h. acid. Harehill, Ayrshire; Endellion, &c., Cornwall ; Cervantes, Spain ; Felsobanya, Hungary ; Mexico ; Canada ; California. 130. STIBICONITE, Sb0 4 , H 2 0. Massive, powdery. H. =4 to 5 5; G. =5 28. Pale yellow. In closed tube yields water. C.c. : antimony 74 9, oxygen 19 6, water 5 5. Goldkronach (Bavaria). 131. VOLGERITE, Sb0 5 , 5H 2 0. Massive and powdery. White. In tube yields water, below red ness. C.c.: antimony 58 9, oxygen 19 3, water 21 8. Constantino in Algeria. 132. ZUNDERERZ (Tinder Ore}. In soft, flexible, tinder-like masses. Colour dark cherry-red to blackish red ; lustre glimmering. Two varieties : one, from Klaus- thai, contains antimony oxide 33, iron oxide 40, lead 16, sulphur 4; the other, from Andreasberg and Klaustlial, seems to be a mixture of jamesonite (82"04 per cent.), mispickel (13 46), and pyrargyrite (4-34). 133. TELLURITE. Yellowish or whitish. Radiated, spherical masses. Gives the

reactions of tellurous acid. Facsebaya and Zalathna, Colorado.