GRUNAUITE. 



Brit. Mus., Case 36. 



M. P. G. Horse-shoe Case, No. 901. 



Grunauite, Nicol, Dana. Cubical. Oc- 

 curs in very small crystals, also granular 

 and_ disseminated. Colour pale steel-grey, 

 inclining to silver-white, with a yellow or 

 greyish tarnish. Lustre metallic. Streak 

 dark grey. Brittle. H. 4-5. S.G. 5-13. 



Comp. Xi S (Ni S3, Bi S5), or Bi S + 

 4Ni S5 = nickel 45-40, bismuth 15-76, sul- 

 phur 38-84 = 100. (v. Kobell.) 



Analysis, (a) by v. Kobell, {b) by Schna- 

 bel: 





(a) 



(h-) 



Nickel 



. 40-65 



22-78 



Bismuth 



. 14-11 



10-41 



Sulphur . 



. . 38-46 



33-10 



Iron . 



. 8-48 



6-06 



Cobalt 



. 0-28 



11-43 



Copper 



. 1-68 



11-56 



Lead. 



. 1-58 



4-36 



100-24 100-00 



BB gives off sulphurous odou:rs, and fuses 

 to a brittle, magnetic globule, colouring the 

 charcoal j^eilow ; with borax gives a nickel- 

 reaction. 



Forms a green solution in nitric acid, 

 the sulphur being precipitated. 



Locality. Griinau, in Sayn-Altenkirchen, 

 in Prussia, usually mixed with Quartz and 

 Copper Pyrites. 



Griinauite is distinguished from Arsenical 

 Iron, which it greatly resembles, by lower 

 specific gravity, and very easily by 'its be- 

 haviour with acids. 



Grunbleierz, Hoffmann, Werner. See 

 Ptro JioRPHiTE, and Mimetite, 



GrIine Eisenerde, Werner. See Hypo- 

 chlorite. 



GRiJNEisENSTEm. See Greex Iron- 

 stoke. 



GrIjnerde, Werner. See Green Earth. 



GrIjnerite, a pure Iron-Augite. S.G. 

 3-713. 



Comp. Fe^ Si^ = protoxide of iron 54-3, 

 silica 57-1 = 100. 



Analysis, from Collobrieres, by Griiner : 

 Silica 43-9 



Alumina 

 Magnesia 

 Lime 

 Protoxide of iron 



1-9 

 1-1 



0-5 

 52-2 



99-6 



Locality. Collobrieres, Dept. de I'Aude, 

 France. 



N'ame. After Griiner, by whom it was 

 analysed. 



GCRHOFIAN. 165 



GRtJNES Uranerz. See Chalcolite. 

 Guanite, E. F. Tescheinacher. See Stru- 



VITE. 



The name Guanite is in allusion to its 

 occurrence in guano. 



Guarinite, G. Guiscardi. A mineral 

 nearly allied in composition to the Sphene 

 of Piedmont (Greenovite). It occurs in 

 pyramidal crystals, with a dilRcult cleavage. 

 Colour honey-yellow. Translucent to trans- 

 parent. Lustre subadaniaiitine : adaman- 

 tine on cleavage faces. H. 6 to 6-5. S.G. 

 3-487. 



Comp. Silica 33-64, titanic acid, 33-92, 

 lime 28-01, iron and peroxide of manganese 

 trace = 95-57. 



Locality. Vesuvius. 



Name. After Prof. G. Guarini, of Naples. 



Gum-lead. A name given to Plumbo- 

 Resinite, because of its resemblance, in ap- 

 pearance, to gum-arabic. 



GuMMi Funerum, Serapion. See As- 

 phalt. 



GuMMiKRz, Breithaupt. An amorphous 

 variety of Pitchblende, containing Vana- 

 dium and Selenium. Colour hyancith-red, 

 yellowish, and reddish-brown. Lustre resi- 

 nous. Soft : breaks between the fingers. 

 Fracture conchoidal. H. 2-5 to 3. S.G. 

 3-9 to 4-18. 



Comp. 4f + 4H (Dufrenoy ) ; Ca^ P + 44f 



li? (Kersten). 



Analysis, by Kersten : 



Peroxide of uranium . . 72-00 



Peroxide of manganese . 0-05 



Silica 4-26 



Phosphoric acid . . . 2-30 



Lime 6-00 



Arsenic .... trace 



Hvdrofluoric acid . . trace 



Water 14-75 



99-36 

 Locality. Johanngeorgenstadt, in Saxony. 

 Name. The name is in allusion to its 

 gum-like appearance. 

 GuMMispATH. See Gum-lead. 

 GuRHOFiAN. GuRHOFiTE. A snow- white 

 and subtranslucent compact variety of Dolo- 

 mite, bearing, in some resi)ects, a strong 

 remblance to Semi-opal. Fracture flat-con- 

 choidal, with sharp edges. 

 Analysis, by Kluproth : 



Carbonate of lime . .70-50 

 Carbonate of magnesia . 29-50 



100-00 

 Locality. Near Gurhof, in Lower Austria, 

 M 3 



t 



