gmelinite. 451 Twin crystals. Twin-face o. Cleavage, s, indistinct. Frac- Tin 6 ' lm I >cr ^ ec ^ conchoidal. Semi-transparent. Lustre vitreous. White, sometimes greyish. Streak white. Brittle, h = 4-0. a = 2-1..,2'2. Chemical characters the same as those of chabasie. Analyses of levyne from Faroe a by Berzelius, I by Arfved- son, c from Skye by Connel, d from Iceland by Damour „ abed . 48-00 48-38 46'30 44’48 ^. lumina 2000 19-28 22-47 2377 ~L lme 8-35 8-70 9-72 1071 Magnesia 0-40 red ox. iron 098 — n a - 2-88 - 1-55 1-38 fi° tastl 0-41 2-60 1-26 1-61 Water 19-30 21-14 19-51 17-41 Is found in cavities in trap at Glenarm in Ireland, Hartfield- moss in lienfrewshire, Dalsnypen in the Faroe islands, Godhavn in Disco, Skaggastrand in Iceland, Skye. 287. GMELINITE.—Ilydrolite; Beudant. Ileteromorpher Kuphon-Spath; Mohs. Chabacit (in part) ; Ilausmann. Gme- hnit; Ilaidinger. Ithombohedral. fig. 447. so uo uu ss" us' 90° O' 90 0 60 0 60 0 30 0 90 0 0 4' VO 36 4 9 s ' 49 56 vu 53 56 vg 18 47 osg, osguv. The faces Combinations. their interseetioiio *..■ «/, o nmiiiHi punuici w muir intersec tions with g; o, rough. The crystals are supposed to be twins. Twin-face o. Fracture uneven. Translucent. Lustre vitreous. White, passing into flesh-red. Streak white. Brittle, ii = 4-5. G = 2-04...212. In the matrass yields water and falls to powder. Fuses heforo the blowpipe into an opaque glass. Is decomposed by hydrochloric acid, forming a perfect jelly of silica. It Si + AlSi 1 + H“, where It is soda, lime and potash.