OLIVINE. 317 salt of phosphorus yields the reactions of iron and silica. With 80 a melts into a brown slag. Is easily and completely decom posed by sulphuric acid, forming a jelly. pla^d b'' 42 ma S nes ^ a part of the Mg being re- Analyses a of the transparent variety (chrysolite), of the oss transparent varieties (olivine), b from the Vogelsberg near lessen, c from Kasalthoff in Bohemia, d from the Iservviese, ^ Ti BOhCmia) ^ ^ r ° m M° n t e Somma (mean of two analyses) Silica Magnesia . . . Protoxide of iron . Oxide of nickel . Oxide of manganese Alumina.... a b C d e / 39'73 4009 40-64 41*54 41-42 40-12 60-13 60-49 60-67 60-04 49-61 44"64 9'19 8-17 8-07 8'66 914 15-32 0-32 0-37 0-33 — — — 0’09 0-20 0'18 0-25 0-15 0-29 0-22 0'19 019 0-06 015 0-14 Analyses of-olivine g from the basalt of Langeac by Berthier, from Greenland by Lappe, i from the talc slate of Syssersk in the Ural (o = 3 p 39...3-43) by Hermann, k by Beck, I from Be Buy j n Vivarais by Walmstedt, m from the Thjorsa lava of flekla (a = 3-220) by Genth:— , 9 h */ k I m 40'8 40-00 4^04 ' 39'21 41-44 43'44 41-6 4309 42’60 44-06 4919 4931 16'4 16-21 17-58 17-45 9’72 6-93 Z} 0-65 0-15 (ca 0'2l) 0"13 0-32 0'06 — — 010 traces from the Otumba iron in South Ame- Silica Magnesia . . . 1 rotoxide of iron . Oxide of nickel Oxide of manganese Alumina .... ■ Anal /sos of olivine rica, o from the Pallas iron by Stromeyer, p from the Pallas iron y Berzelius, q from the Pallas iron, r from Monte Somma, oth by Walmstedt, s of the partially decomposed olivine (hya- osiderite) having a semi-metallic lustre and brown tarnish (o = 2 8 ?6) from the Kaiserstuhl in Baden by Walchner:—■ Silica . Magnesia .' f rotox. i ron ^°tox. man. Alumina . Oxide of tin n 0 P 7 r 38'25 38-48 40-80 4083 40-08 49-08 48-42 47-35 47-74 44-22 11'75 11-19 11-72 11-63 15-20 o-ii 0-34 0-43 0-29 0-48 — 0-18 — — 0‘18 — — 0’17 — k s 31'63 32’4.0 28-49 0-48 2',21 2-79 i> 3
