276 HYDROUS EARTHS, OXIDES, AND ACIDS. pm 49° 49' nl 38 18 scl 62 46 nb 66 25 vv f 67 24 vv" 92 24 v'v” 61 15 %a 68 38 ''' XX 74 28 FIG. 300. nri 00 O 66' SS 25° 47' mi' 47 10 ss" 63 50 rin" 103 24 s's" 70 2 PP„ 49 11 99 17 21 pp p’p" 59 80 6 22 99' 9’f 64 67 60 42 sd 64 59 FIG. 301. Ur 1 Combinations, cm, cmk, vrnk, gnvmldx, usepvmkld. The faces c striated parallel to their intersections with u; u striated parallel to their intersections with p; the faces of the zone mm striated parallel to their intersections with each other. Most of the faces smooth and bright. Twins. Twin-face e. Cleavage. a, very perfect and easily obtained; m, perfect; b, c traces. Opaque. Lustre metallic, imperfect. Dark steel-grey... iron- black, brownisb-black, velvet-black ; sometimes iridescent. Streak reddish-brown. Brittle. 11 = 3‘6...4'0. G = 4’22... 4'34. Conducts electricity. In the matrass yields water. Infusible before the blowpipe. Imparts an amethyst colour to borax and salt of phosphorus in the outer flame, which disappears in the inner flame. Solublo in hydrochloric acid -with disengagement of chlorine. Very slightly soluble in concentrated sulphuric acid, colouring it faintly red. MnH, manganese 62-65, oxygen 27'24, water 10-21. Analyses of manganite a from Undeniis by Arfvcdson, I from Ihlefeld by L. Ganelin, c, d from Ihlefeld by Turner:—