GLAUCODOT. 

 partly dissolved. H. 2-5 to 3. S.G. 2-6 

 to 2-85. 



Fig. 211. 



Comp. Sulphate of soda and lime, or 



CiXa + ^Ca) 's = sulphate of soda oM, sul- 

 phate of lime 48-9-100, 



Analysix, from Atacaraa, by Hayes : 

 Sulphuric acid . . . 67-22 



Soda 11-32 



Lime . . . . . 20-68 

 Iron 0-14 



99-36 

 BB decrepitates and then melts to a clear 

 glass. 



Localities. In crystals, imbedded in Rock 

 Salt and clay, at the salt mines of Villa 

 Rubia, near Ocana; and Aranjuez, near 

 Madrid, in Spain. Aussee and Ischl, in Upper 

 Austria. The salt mines of Vic, in France 

 (see PoLYHALiTE DE Vic). The province of 

 Tarapaca, in Peru, with Hayesine, &c. 



Name. Glauberite is so called in conse- 

 quence of its containing a very large amount 

 of Glauber's salt. 

 Brit. Mus., Case 52. 



Glaucodot or Glaucodote, Breithaupt. 

 A cobaltic variety of Mispickel, with which 

 it nearly agrees in crystallization, and also 

 in composition, except in the replacement of 

 one-third of the cobalt by iron. It is of 

 a grevish, tin-white colour, with a metallic 

 lustre'. Streak black. H. 5. S.G. 5-97 to 6. 

 Comp. (Co, Fe) As + (Co, Fe) S2 = sulphur 

 19-4, arsenic 45-5, cobalt 23-8, iron 11-3 = 100. 

 Analysis, from Huasco, in Chili, by Plattner : 

 Sulphur . . . .20-21 

 Arsenic .... 43-20 

 Cobalt . . . .24 77 

 Nickel .... trace 



Iron 11-90 



Silica trace 



100-08 



BB gives the reaction of cobalt, iron, sul- 

 phur, and arsenic. 



Gives only a trace of arsenic when heated 

 in a glass closed at one end. 



Localities. In mica-schist, associated with 

 Cobaltine, in the province of Huasco, in 

 Chili : and at Orawitza, in the Bannat, with 

 Calcite. 



Name. From y^^xvyJ,-, grey. 



Brit. Mus., Case 12. 



GLAUCOPHANE. 155 



Glaucolite, Fischer. A massive variety 

 of Scapolite of a lavender-blue or indigo-blue 

 colour, occasionally passing into green, some- 

 what resembling blue Cancrinite. Lustre 

 vitreous. Translucent at the edges. Frac- 

 ture splintery. H. 5 to 6. S.G. 2 65 to 2-67. 



Comp. R3 Si2 + 2A1 



Si. 





Analysis, from Lake Baika 



I, by Von Rath : 



Silica . 





. 46-01 



Alumina 





. 21-72 



Peroxide of iron . 





. 1-49 



Lime . 





. 15-68 



Carbonate of lime. 





. 1-68 ' 



Magnesia 





. 0-46 



Potash 





. 0-56 



Soda . 





. 4-57 



Water . 





. 0-47 



97-64 



BB whitens and fuses with difficult}-. 

 Dissolves slowly with effervescence in borax 

 and salt of phosphorus. 



Localities. In veins in granite, in the 

 vicinity of the river Sludianka, beyond Lake 

 Baikal, in Siberia. Laurvig, in Norway, 

 accompanied by Elteolite. 



Name. From j'Aay^of, sea-green, and a/0o?, 

 stone. 



Glauconite. Occurs in green grains, or- 

 in small greenish masses, in the green sand- 

 stone of various countries, as in the Upper 

 Greensand of the south of England and 

 Havre; in the Greensand of BUderich, near 

 VVerl, in Westphalia; Gay Head, Massa- 

 chusetts, U. S., &c. 



Some of these varieties (as the first-men- 

 tioned) may be referred to Augite, others to 

 Green Earth or Chlorite. 



Analysis, from Gay Head, by S. L. Dana: 

 Silica . . . . " . 56-70 



Alumina 



Protoxide of iron 

 Magnesia 

 Lime . 



. 13-32 

 . 20-10 

 . 1-18 

 . 1-62 



99-92 



Name. From y>^eivxof, sea-green. 



Glaucophane, Hausrnann. Probably 

 the same as VVichtyne. Occurs in indis- 

 tinct, long, and thin six-sided prisms, longi- 

 tudinally striated ; also granular-massive. 

 Colour blue, lavender- blue, bluish-black, 

 greyish. Lustre vitreous to pearly. Trans- 

 lucent to opaque. Streak greyish- blue. 

 Powder slightly magnetic. Brittle. H. 5-5. 

 S.G. 3-108. 



Comp. (iK3 + ii^)Si3. 



