892 SILICATES. Fracture conchoidal, seldom observable. Transparent...trans lucent on the edges. Lustre, on c pearly inclining to adamantine; on the other faces vitreous. Of various shades of white, grey, green rose-red peach-blossom-red, violet; frequently silver-white by reflected right, rose-red by transmitted light. Streak white. In thm leaves elastic, n = 2 -o... 3 -o. a =Vs...3-0. e ore t e blowpipe melts into a white or grey glass, some- times mto a black magnetic bead. Imparts a purple colour to tfle flame. Is acted upon more or less by acids. The variety om Altenberg is completely decomposed by sulphuric acid. Analyses of lepidolite a from Eozena by C. Gmelin, b from Eozena by Kralowansky c from Chursdorf by C. Gmelin, d Sf /r •> ? Gmehn ’ e from Cornwall, brown, by Turner,/ locality unknown, yellow, by Regnault:— Silica . . . Alumina Red ox. iron Protox. mangan. Magnesia . . Potash . . . Lithia . . . Hydrofluoric acid Phosphoric acid Water . . . a b C d e / 49'06 40-08 62-25 46-23 40'06 40-78 33-61 34-01 28-36 14-14 22-00 19-88 — — — 17-07 27-06 13-22 1-40 I’08 3-06 4'67 1-79 0'41 0-41 — — 4-19 4-19 6-00 4-00 4-30 8*70 3'50 3'68 4-79 4-21 2*00 4*15 3-45 | • 3-60 6-07 8'63 2*71 4*26 o-ii j — — . _ 4-18 4-16 trace 0-83 Analyses of lepidolite y from Zinnwald, h from Altenberg, • from Uto, k from the Ural, I from Cornwall, grey, all by Turner, m perhaps from Eozena by Itegnault Silica Alumina 24 Protox. iron Protox. mangan. . Potash .... Lithia .... Hydrofluoric acid y h i Jc I m 44-28 40-19 60-01 60-35 60-82 62-40 24-53 22-79 28-17 28-30 2133 26 80 1133 19-78 — — 9-08 1-66 2-02 1-08 1-23 trace 1-60 0-47 7-49 0-60 0-04 9-86 0-14 4-00 3-06 6-67 6-49 4-05 4-85 6-14 3-00 4-11 5-20 4-81 4-40 hv^T^'V 88 J. e P^°^f e n > 0 from Juschakowa near Mursinsk LoW™ T AItenber « b f Steil b from Zinnwald q by 2-8481 asT’ ^ * from Zm nwald, t of lepidolite (a = Lna m Ai> 8l d i W1 ^/ ed imposing tourmaline from Ro- zena in Moravia, both by Eammelsbergt-
