Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/418

Rh 400 MINERALOGY or adamantine, pearly on OP. Yellowish white, inclining to grey, green, yellow, or brown. C.c. : 81 98 oxide of lead, 8 03 car bonic acid, 8 12 sulphuric acid, 1 8 water. Lead- hills, Taunton, Nertchinsk, Granada. Maxite from Sar dinia. 307. SUSANNITE, 3PbC + Pb S. Rhombohedral ; R 72 29 . Cl. basal, perfect. H. =2-5; G. =6-55. White, green, yellow, brownish. Resinous to adamantine ; pearly on the cleavage faces. Powder white. C.c. : 72 - 5 carbonate and 27 &quot;5 sulphate of lead. From the Susanna mine at. Leadhills, but very rare ; Fi- 890 (sp. 807). also in large dark crystals from the Bauat. Fig. 391 (sp. 307). ANHYDROUS SULPHATES. 308. ARCANITE (Glaseritc), K 2 S. Right prismatic. Acute pyramids, with ooP 120 24 ; dimorphous and also rhombohedral, with R 88 14. Mostly in crusts, or pul verulent. Cl. basal, imperfect. H. =2&quot;5 to 3 ; G. = 27. Pellucid; vitreous or resinous. Colourless or white. C.c.: 54 potash and 46 sulphuric acid. Lavas of Vesuvius and other volcanoes. 309. MASCAGNINE, (NH 4 ) 2 S. Right prismatic. &amp;lt;xP 121 8 ; but chiefly in crusts and stalac tites. Cl. perfect; sectile. H.=2 to 2 5 ; G. =17 to 1 8. Pel lucid; vitreous. Colourless, white, or yellowish. Taste pungent and bitter. C.c. : 25 9 ammonia, 60 5 sulphuric acid, and 13 6 water. Near volcanoes, as Etna, Vesuvius, the Solfatara, the Lipari Islands, in the marshes near Siena, and in ignited coal-beds, as at Bradley in Staffordshire. 310. THENARDITE, Na 2 8. Right prismatic. Acute pyramids P, with OP and ooP, in crusts and druses. Cl. basal, perfect; fracture uneven. H.=2 5; G. = 2 6 to 27. Pellucid; vitreous. White. C.c. : 43 82 soda and 56 18 sulphuric acid. In salt deposits near Aranjuez (Spain) and at Tarapaca (Peru) 311. GLAUBEKITE (Brongniartinc), Na^S + CaS. Oblique prismatic, C 68 16. OP, - P, or with ooP (P, f, M, fig. 392). Cl. basal, perfect; along ooP traces. H. = 2 5 to 3; G. =275 to 2 85. Translucent; vitreous to resinous. Colourless. C.c. : 51 sulphate of soda, and 49 sulphate of lime. Villarubia in Spain, Vic, Berchtesgaden, near Brugg in Aargau, Aussee and Lschl in Austria ; Tarapaca in Peru, with 1 to 5 boracic acid. 312. ANHYDKITE (Karstenite), CaS. Right prismatic. ooP 90 4. Chiefly granular, or almost com pact or columnar. Twins rare. Cl. macrodiagonal and brachy- diagonal, both perfect; basal perfect. H. =3 to 3 5 ; G. =2 8 to 3. Transparent or translucent ; vitreous ; on ool oo pearly. Colourless or white, but often blue, red, or grey ; streak greyish white. C.c. : 5875 sulphuric acid and 41 25 lime. The crystalline, or Muriacite, occurs in the salt-mines of Bex, Hall in Tyrol, and Aussee in Styria, also at Sulz, Stassfurt, and Bleiberg. Compact at Ischl in Austria, Berchtesgaden, Eisleben, and the Harz. Granular, or Vulpinite, near Bergamo. The contorted, or Gckrosstein, chiefly at Wieliczka and Bochnia. 313. BARYTE (Heavy Spar), BaS. Right prismatic. Poo (&amp;lt;/) 78 20 ; Poo (/) 105 22 ; &amp;lt;xP2 (d) 77 44 ; also ooPoo (c) (figs. 125, 126, 127, but in a different position, d, d being placed vertical). The crystals show very many forms and combinations, and are tabular or columnar, often in druses or groups ; also foliated, fibrous, granular, or compact. Cl. brachy- diagonal perfect, along Poo less perfect; basal, traces. H.=3 to 3*5 ; G. =4 3 to 47. Transparent to translucent; vitreous or resinous. Colourless and white, but generally reddish white, or flesh-red, yellow, grey, bluish, greenish, or brown. B.B. decrepitates violently, and fuses very difficultly, or only on the edges, colouring the flame yellowish green ; not soluble in acids. C.c. : 34 3 sulphuric acid and 657 baryta, but occasionally with 1 to 15 sulphate of strontia. Very common, chiefly in veins, either alone or accompanying ores. Crystals at Arran, Strontian, Elie, Sutherland ; Dufton, Bohemia, Felsobanya and Kremnitz in Fig. 393. Hungary, Auvergne, and United States. Columnar at Freiberg. The radiated from near Bologna, or the Bolognese Stone, phos phoresces in the dark. Massive, or Caivk, from Derbyshire and Staffordshire, Leadhills, and Arran. Lime Barytes, from Derbyshire, Strontian, Freiberg, seems a mixture with sulphate of lime ; crystals tabular, in rosettes and other groups; G. = 4 to 4 3. Hepatite, dark grey, from carbona ceous matter ; Kongsberg. Allmnorpliite, scaly, white, and pearly, near Rudolstadt, agrees essentially with barytes. 314. BARYTO-CELESTINE, 2SrS + Ba S. Radiated and foliated. Bluish white. Brit tie and friable. H. = 2 5;G. =3 92. Difficultly fusible. Lake Erie, Upper Canada, and Binnenthal. 315. CELESTINE, SrS. Right prismatic ; forms like barytes and anglesite. Poo (o) 104 8 ; Poo (M) 75 58. Usual combinations Poo, Poo, oo Poo ; or this with ooP2 (d) ; also columnar and foliated ; or fibrous, fine granular, or compact. Cl. macrodiagonal, perfect ; along Poo less perfect. H. =3 to 3 5 ; G. =3 9 to 4. Transparent or translucent ; vitreous or resinous. Colourless, but usually bluish white to indigo-blue, and rarely reddish or yellowish. B.B. decrepitates and fuses easily to a milk-white globule ; colours the flame carmine-red. Distinguished from barytes by a splinter, after ignition in the inner flame, on being moistened with h. acid, and held in the blue border of the flame of a candle, colouring this of a lively purple-red. Scarcely affected by acids. C.c.: 43 6 sulphuric acid and 56 4 strontia, but often some baryta or lime. Tantallon Castle, Calton Hill, Clachnaharry ; near Bristol and Knares- borough ; sulphur-mines of Girgenti and other parts of Sicily, Herrengrund in Hungary, Bex, Salzburg, Monte Viale near Verona, and Meudon and Montmartre near Paris. Used for producing a red light in pyrotechnic mixtures. 316. ANGLESITE, PbS. Right prismatic. ooP 103 43 ; Poo 75 35. The crystals, of many forms and combinations, are short prismatic, pyramidal, or tabular. Cl. prismatic along &amp;lt;xP, and basal ; fracture conchoidal ; very brittle. H. =3; G. =6 2 to 6 35. Transparent or translucent ; adamantine or resinous. Colourless and white, but occasionally yellow, grey, brown, or blue ; streak white. De crepitates in candle ; B. B. on charcoal fuses in the oxygen flame to a milk-white bead ; very difficultly soluble in acids, wholly in solution of potash. C.C.: 737 Fl S- 394. Fig. 395. lead protoxide and 26 3 sulphuric acid. Leadhills (fig. 397), St Ives in Cornwall, Derbyshire, Parys mine in Anglesea, Zellerfeld, Klausthal, Baden- Fig. 396. Fig. 397. weiler, Siegen, Silesia, Linares, Phcenixville in Pennsylvania. 317. LANARKITE, Pb S + Pb. Oblique prismatic. tP4950. Cl. basal, perfect; sectile; thin lamina; flexible. H. =2 to 2 &quot;5 ; G. =6 3 to 67. Transparent; Fig. 398. resinous or adamantine ; on OP pearly. Greenish or yellowish white, inclining to grey ; streak white. B.B. on charcoal fuses to a white globule containing metallic lead ; partially soluble in n.