EUDIALYTE. 357 Very tough, n = 3'75. g = 2'974. Phosphoresces with a blue light when struck with a hammer or heated. Becomes feebly electric by pressure and also when heated. Before the blowpipe melts into a clear bead tinged with violet. In borax fuses readily into a clear amethyst-coloured glass. 3CaSi +G 3 Si s + NaF, silica 48'6, lime 26-3, glucine 11-9, so dium 7'3, fluorine 5'9. Analysis by Erdmann:— Silica 47'82 Glucine irsi Lime 25 00 Protoxide of manganese . roi Potassium 0’26 Sodium 7*59 Fluorine e-17 Is found imbedded in syenite in the Lammon rock below Stokon at the mouth of the Langesund-fjord in Norway. 200. EUDIALYTE.—Eudyalite; Phillips, Hauy. Rhom- boedrischer Ahnandin-Spath; Mohs. Eudialyt; Iiausmann, Haidinger. Rhombohedral. 100,111 = 67° 42'. 0 111, a oil, b 211, r 100, e oil, z 211, s 111, t 021. aa' 60° 0' rr’ ioe° 30' 30 0 88 116 4 FIG. 375. bb" 60 0 ta 13 69 zo 31 22 tr 22 46 TO 67 42 ze 42 2 bo 90 0 re' 63 15 eo 60 38 T8 68 2 SO 78 25 ra 36 45 6'\ r b to 81 11 ae 47 68 53 36 as" 31 68 ° V " ee' 84 4 Combinations, ozra, ozrs, ozrba, ozerba, ozersba, ozerstba. Cleavage. 0, distinct; z, less distinct; r, a traces, seldom observable. Fracture conchoidal... uneven. Translucent on the edges...opaque. Lustre vitreous. Dark peach-blossom-red... brownish-red. Streak w'hite. Slightly brittle, h = 5-0...5-5. G = 2'84...2'95. In tlie matrass yields a little moisture. Before the blowpipe melts into a greyish-green opaque slag. With borax fuses