.562 



MINERALOGY. 



OBDEH IV 

 GLANCE. 



fii'yctogno- Geognostic and Geographic Situations. Occurs in 

 s y- veins that traverse transition rocks at Zilla, in the Claus- 

 V -*~V~^~' thai in the Hartz, and in other districts. 



Use. It is worked, both as an ore of copper and as 

 an ore of silver. 



T|N i- v . GENUS VI. TIN-PYRITES. 



uiTEs. Steel grey, inclining to brass yellow. Sp. gr. = 4.3 



,5.0. 



This genus contains but one species, viz. Common 

 Tin Pyrites. 



Common I. COMMON TIN PYRITES, Jameson. Zinnkies, Wcr. 



Tin Py- External Characters. Massive. Colour intermediate 



rites. between steel-grey and brass-yellow. Occurs massive 



and disseminated. Internally glistening or shining, and 

 lustre metallic. Fracture uneven, and sometimes con- 

 choidal. 



Constituent Parts. Tin, 26.50 



Copper, 30.00 



Iron, 12.00 



Sulphur, 30.5099 

 Klaprolh, Beit. b. v. s. 230. 



Geognostic and Geographic Situations. It has been 

 hitherto found only in Cornwall, where it occurs in pri- 

 mitive rocks. 



ORUER IV. GLANCE. 



Metallic. Grey, black. Hardness = 1 4. Sp. gr. 

 = 4. 7.(j. If the specific gravity is under 5, with sin- 

 gle imperfect cleavages, the colour is lead- grey. If above 

 7.4, is lead-grey. 



GENUS I. COPPER-GLANCE, OR VITREOUS 

 GLANCE. COPPER, Jameson. 



Kupfer-Glanz, Molts. 



Cleavage rhomboidal. Blackish lead grey. Sectile 

 and nearly malleable. The intensity of the lustre in- 

 creased in the streak. Hardness = 2.5 3.0. Sp. gr. 

 = 5.55.8. 



This genus contains one species, viz. Rhomboidal 

 Copper Glance. * Variegated Copper. 



Rhomboid- L RHOMBOIDAL COPPER GLANCE, or VITREOUS COP- 

 al Copper PER ORE, Jameson. Kupferglas, Werner. 

 Glance. Rhomboid unknown. Cleavage in the direction of 



lateral planes of a six-sided prism. 



External Characters. Colour blackish lead-grey. 

 Occurs massive, disseminated, and crystallized on six- 

 sided prisms and six-sided pyramids. Internally shin- 

 ing, glistening and glimmering, and metallic. Frac- 

 ture uneven and conchoidal. Siberia. 

 Constituent Parts. Copper, 78.05 

 Iron, 2.25 

 Sulphur, 18.50 

 Silica, 0.75 100.00 



Geoanostic and Geographic Situations. It occurs in Oryctogno- 

 veins in primitive, transition, and secondary rocks, in S X- 

 various mining countries, as Cornwall, Arendal, Kongs- 

 berp, Thuringia, &c. 



Uses. Copper is extracted from it, but it is not so 

 easily reduced as copper-glance. It yields from 50 to 

 70 per cent, of copper. 



Klaprolh, Beit. b. ii. s. 179- 



Geognostic and Geographic Situations. It occurs in 

 veins and beds in primitive rocks ; also in beds in bi- 

 tuminous marl-slate, and in floetz amygdaloid j and is 

 found in Scotland, England, Germany, Sweden, Hun- 

 gary, &c. 



Variegated * VARIEGATED COPPER, Jameson. Buntkupfererz, 

 Copper. Werner. 



External Characters. Its fresh colour is intermediate 

 between copper-red and pinchbeck-brown : it, how- 

 ever, soon acquires a variegated tarnish. Occurs mas- 

 sive, disseminated, and crystallized in six-sided prisms. 

 Internally shining or glistening, and lustre metallic. 

 Fracture conchoidal. From Rudelstadt in Sileia. 



Constituent Paris. Copper, 

 Sulphur, 

 Iron, 



. Oxygen, 

 Klaproth, 



58 



. 19 

 18 



5100 



Beit. b. ii. s. 286. 

 4 



GENUS II. SILVER GLANCE, OR VITREOUS 



SILVER, Jameson. GLAKCE. 



Silber-Glanz, Mohs. 



Cleavage rhomboidal, or not discernible. Blackish 

 lead-grey, and iron-black. If blackish lead-grey, the 

 specific gravity=6.9 and more. Hardness 2.0 2.5. 

 Sp. gr. = 5.77-2. 



This genus contains two species, viz. Hexahedral 

 Silver Glance, and Rhomboidal Silver Glance. 



I. HEXAHEDRAL SILVER GLANCE, Jameson. Hex- Hexabedra 

 aedrischer Silber Glanz, Mohs. Silver 



Tessular. Cleavage not discernible. Sp. gr. = 6.9 Glance - 

 7.2. 



External Characters. Colour dark blackish lead- 

 grey. Generally occurs massive, sometimes in various 

 particular external shapes, and crystallized in cubes, oc- 

 tahedrons, and rhomboidal dodecahedrons. Externally 

 shining and glistening. Internally shining and glisten- 

 ing, and lustre metallic. Fracture uneven, conchoidal. 

 Completely malleable. Flexible, but not elastic. 



From Himmelbfiirst. 



Constituent Parts. Silver, 85 



Sulphur, 15100 Klaprolh. 



Geognostic and Geographic Situations. It is one of 

 the most frequent of the ores of silver, and there are 

 few formations of that metal which do not contain it. 

 It occurs in Scotland, England, Germany, and many 

 other mining countries. 



Uses. It is highly valued as an ore of silver. 



II. RHOMBOIDAL SILVER GLANCE, or BRITTLE SIL- Rhomboid 

 VER GLANCE, Jameson. Sprodglaserz, Werner. al Silver 



Rhomboid unknown. Sp. gr. = 5.7 6.1. 

 External Characters. Colour intermediate between 

 iron-black and blackish lead grey. Generally dissemi- 

 nated, and sometimes crystallized in equiangular six- 

 sided prisms, and six-sided pyramids. Externally high- 

 ly splendent. Internally shining, inclining to glisten- 

 ing, and lustre metallic. Fracture alternates from small 

 conchoidal to fine-grained uneven. Lustre not increas- 

 ed in the streak. Sectile. 



Constit. Parts. Silver, . . 66.50 

 Sulphur, . 



Antimony, . 10.00 



Iron, . . 5.00 



Copper and Arsenic, 0.50 



Earthy substances, 1.00 95.00 



Klaproth, Beit. b. i. s. 166. 



Geognostic and Geographic Situations. It occurs in 

 veins that traverse gneiss, clay- slate, and porphyry, in 

 Saxony, Bohemia, and Hungary. 



GENUS III. GALENA OR LEAD-GLANCE. GALEKA. 

 Tessular. Pure lead-grey. Hardness = 2.5. Sp. 

 gr. 7.0-7.6. 



This genus contains but one species, viz. HexahedraJ 



Galena. 



1. HEXAHEDRAL GALENA, or LEAD-GLANCE, Jame- Hexahd 

 son Hexaedrischer Bleiglanz, Mohs. Galena. 



Tessular. Cleavage hexahedral. Hardness = 2.5. 

 Sp. gr. = 7.07.6. 



This species is divided into two subspecies, viz. 

 Common Galena, and Compact Galena. 



