GIFTKIES. 



Comp. (R3ifc)8 iii^ + SH. 



Analysis (mean of three), from Diana, by 

 Prof. Brush : 



Silica 45-67 



Alumina .... 31'51 

 Peroxide of iron . . 0-27 



Protoxide of iron . . . 0-77 



Lime 2-20 



Magnesia . . . * . 3-48 



Soda 0-88 



Potash 8-21 



Carbonate of lime . . 0o2 

 Water 6-97 



100-28 



BB becomes opaque and fuses to a white 

 enamel. 



Localites. Akulliarasiarsuk in Greenland, 

 imbedded in- compact Felspar. United 

 States, at Diana, Lewis co., N. Y., in gra- 

 nular limestone with Pyroxene and J\lag- 

 netic Pyrites. 



Name. After Sir C. Giesecke, by whom it 

 was first brought from Greenland. 



GiFTKiES. See Mispickel. 



GiGANTOLiTE. The name given by ISTor- 

 denskiold to a hydrated lolite (correspond- 



ing to lolite + 3H), found in gneissoid 

 granite at Tamela in Finland, It is of a 

 greenish -grey colour, with a vitreous and 

 Avaxv lustre, approaching to submetallic, 

 S.G."'2'862 to 2-878. 



BB fuses witli intumescence to a light 

 greenish slag. 



Analysis, from Tamela, by Marignae : 



Silica .... 



. 42-59 



Alumina 



. 26-78 



Peroxide of iron . 



. 14-21 



Potash .... 



. 5-44 



Magnesia 



. 2-72 



Protoxide of manganese 



. 1-07 



Water .... 



. 5-70 



98-51 

 Brit. Mus., Case 32. 



GiLBERTiTE, Thomson. A hydrous Mus- 

 covite ; a variety of Margarodite. H. 2-7. 

 S.G. 2'6 to 2-8. 

 Analysis, from Cornwall, by Lehunt : 

 Silica 4515 



Alumina 

 Magnesia 

 Lime . 



Protoxide of iron . 

 Water . . 



40-11 

 1-90 

 4-17 



2-43 

 4-25 



98-01 



GISMONDINE, 153 



Locality. Stenna Gwynn, near St. Austell, 

 in Cornwall, in considerable masses, of a yel- 

 lowish-white colour, with granite and Fluor. 

 M.P.G. Horse-shoe Case, No. 1001. 

 GiLLiNGiTE. The name given by Her- 

 mann to the varieties of Hisingerite from 

 Gillinge and Orijerivi in Finland. 



Analysis, from Gillinge, by Rammelsbevfj : 



Silica 32-18 



Peroxide of iron . . 30-10 



Protoxide of iron . . 8-63 



Lime 5-50 



Magnesia 4-22 



Water .... 19-37 



100-00 

 Brit. Mus., Case 26. 



GiOBERTiTE, Beudant. A variety of 

 Magnesite from Baumgarten, in Silesia ; 

 named after Giobert, Avho first pointed out 

 the presence of carbonate of magnesia in 

 the earthy varieties of Magnesite. 

 Analysis, by Stromeyer : 



Magnesia .... 48-36 

 Carbonic acid . . . 50*32 

 Peroxide of manganese . 0-21 

 Water . . . .1-39 



99-18 



GiPSiTE, Beudant. See Gibbsite. 



GiRASOL. The name given by the French 

 to Fire-opal, and by JVallerius §- De Born 

 to milk-white translucent Opal. The name 

 Girasol is derived from gyro, to turn, and 

 Sol, the SMw, because it constantly reflects a 

 reddish colour when turned to the sun or 

 any bright light. Sometimes it strongly 

 resembles a translucent jelly. 



GiSMONDiNE, Beudant, "Phillips. Pyra- 

 midal. Occurs in octahedrons, either separate 

 or clustered into mammillated forms with a 

 drusy surface. Colour bluish- white, greyish, 

 reddish. Lustre splendent. Transparent to 

 translucent. H. 4-5. S.G. 2-265. 



BB whitens, intumesces, and melts to a 

 milky glass: at 100° C. (212° F.) loses one- 

 third of its water. 



Easily dissolves in acids and gelatinises. 



Comp. (Ca, K)3 Si -f 2 Al Si + 9H. 



Analysis by Marignae : 



Silica 35-88 



Alumina .... 27-23 



Lime 13-12 



Potash 2-85 



Water 21-10 



100-18 

 Locality. Capo di Bove, near Rome; 

 associated with Phillipsite. 



