Volltext Seite (XML)
282 SILICATES. Anorthie. 110,110 = ei° so'; 100,110=59° o'; 111,110=4,7° s'; 001,110 = 48° 0'; 001,110 = 80° 30'. a_ 100, c_ 001, y 101, x 101, m 110, t TlO, v ill, r 111, s ill, u 111. ma 69° 0' mt 61 30 ta,' 59 30 ya 51 21 ca 75 42 xa 106 10 vm 39 27 cm 80 33 Vm 131 25 rt 47 3 Ct 95 3 st 137 55 Combinations, camt, camtvrsu. Twins. Twin axis, the axis of the zone omt. oc = 29° 2'. Cleavage, c, very perfect and easily obtained. Transparent...translucent. Lustre pearly. The optic axes seen through the faces c appear to make with each other an angle of about 8°. Colourless, white, greyish- white, yellowish-white. Streak white. 11 = 1. o = 1-48. Unctuous to the touch. Taste faintly acid and bitter. In the matrass yields water. Exposed to the flame of a lamp intumesces, and melts into a transparent bead, which on being rubbed, without being isolated, acquires resinous electricity. Imparts a green colour to the blowpipe flame. Soluble in 26 parts of water at 19° c, and in 3 parts of boiling water. Soluble in alcohol. The solution burns with a green flame. Boll 5 , boracic acid 60’38, water 43’62. In crystalline scales and crusts, granular and stalactitic. Is found mixed with sulphur in crevices in the islands of Yulcano and Stromboli, and appears to have been produced by sublimation along with the vapour of water; also in solution in the water of hot springs in the neighbourhood of Sasso in Tuscany. SILICATES. 156. STAUROLITE.—Staurolite ; Phillips. Staurotido ; Hauy. Prismatoidischer Granat; Mohs. Staurolith; JLLaus- mann, Hai dinger. Prismatic. 011,010=34° 38 ; 101,001=34° 26'; 110,100=01° 40'.