MINERALOGY. 



555 



I'lAlUCM 



O.i. 



Indivisible 



Finland. 



Constituent Paris. Oxide of Tantalum, 83 



Oxide of Iron, . 12 



Oxide of Manganese 8103 



l'au<juelin, in Haiiy, Tabl. p. SOS. 

 Geognoslic and Geographic Situation*. It occurs dis- 

 seminated in a coarse red granite, at Brokarns. 

 GENOS VI. URANIUM-ORE. 



Uran-Erz, Moht. 



Form unknown. Streak black. Hardness = 5.5. 

 Sp. gr. = 6.*, 6.6 



This genus contain* one Specie?, viz. Indivisible Ura- 

 nium-Ore. 



1. INDIVISIBLE or UXCLEAVABLE URANIUM-ORE, 

 or unclear- Jameson. Untheilbares Uran-Erz, Moht. Uranpe- 

 bit ur.. ebtn Werner. 

 iumor.. Uncie^able. Renifonn. Massive. 



External Character* Colour black. Generally 



occurs massive, seldom disseminated, sometimes reni- 

 form; also in granular, lamellar, and prismatic concre- 

 tion. Iternally shining, lustre resinous, inclining to 

 semi-metallic. Fracture conchoidal, which passes into 

 coarse-grained uneven. Opaque. j^rhi^^i^i 



Comfit. ParU Oxide of Uranium, 86.5 

 Black Oxide of Iron, 2.5 

 Galena or Lead-glance, 6.0 

 Silica, . . 5.0 



Klaprotk, Beit. b. ii. s. 221. 



Geognotiic and Geographic Situation*. It occurs 

 principally in veins in primitive rocks, in Cornwall and 

 other countries. 

 Crmrcif GENUS VII. CERIUM-ORE. 



Cerer-erz. Moht. 



Cleavage either prismatic or invisible. No metallic 

 lustre. Streak white, grey. Hardness = 5.5. Sp. 

 gr. = 3.5, 5.0. 



' PHISMATIC CIRICM-ORK, Jameion. 



cerium ore. Prism = 117. Sp. gr. = 4.0 5.3. 



External Character*. Colour brownish-black. Oc- 

 curs massive, and crystallized in oblique, four, and in 

 six-sided prisms. Internally shining, and resino-me- 

 tallic Fracture conchoidal. Opaque. Affords * 

 grecnish.frey coloured streak. 



Geognottic and Geographic Situations. Occur* in 

 granite rock in West Greenland, where it was first dis- 

 covered by Professor Giesccke of Dublin. 



Udmrfbk 2. UxcLtAVABLECciuM-OR,or CEKITE, Jameton^- 

 er,un,.ot. Untheilbre Cerer-e, Moht. 



Massive. Hardness = 5.5. Sp. gr. = 4.6, 5.0. 

 External Character* Colour red and brown. Oc- 

 curs massive, and disseminated. Internally glimmer- 

 ing and resinous. Fracture fine splintery. Opaque. 

 Its streak is greyish-white. 



Constituent Part*. Oxide of Cerium, 54.0 

 Silica, . 34.50 



Oxide of Iron, 3.50 



Lime, . . 1.25 

 Water, . . 5.0098.75 

 Klajrroth, Beit. b. iv. s. 147. 



Geoenottic and Geographic Situation* Occurs in a 



bed of copper-pyrites in Westmanland in Sweden. 

 CBMXX- GENUS VIII. CHHOME-ORE. 



" Chrom-er, Moht. 



Prismatic. Streak brown. Hardness = 5.5. Sp. 

 gr. = 4.4. 4.5. 



This genus contains one species, viz. Prismatic 

 Chrome-Ore. 

 I'rumatie 1. PRISMATIC CHROME-ORE, Jameson Prismatisch. 



cbron.e. es Chrom-eTZ, Moht. 



Prismatic. Pyramid unknown. Cleavage prisma- 

 toidal. 



Constituent Part*. 



External Ch trader* Colour between steel-grey and Oryetogn*. 

 iron-black. Occurs massive, disseminated, and in gra- *J- 

 nular distinct concretions ; also crystallized in oblique '* "V^** 

 four-sided prisms, acuminated with four planes. In- 

 ternally shining or glistening, and the lustre imperfect 

 metallic. Fracture small and fine-grained uneven, 

 sometimes passing into small and imperfect conchoidal. 

 Opaque. 



P/tytical Characters. Some varieties are ciagnetical, 

 others are not 



Chemical Character!. It is infusible before the blow- 

 pipe. Melted with borax, it forms a beautiful green- 

 coloured mass, very different from the dark green- 

 coloured glass formed when borax and magnetic iron- 

 ore are melted. 



Stiria. 



.Oxide of Iron, 33.00 

 Oxide of Chrome, 55.50 

 Alumina, . 6.00 

 Silica, . . 2.00 

 Loss by heating, 2.00 98.50 

 Klaproth, Beit b. iv. s. 132. 



Geognottic and Geographic Situations. Occurs in ser- 

 pentine and talc in the Shetland islands, and in vari- 

 ous quarters in the continents of Europe, Asia, and 

 America. 



Use*. When the chromic acid, which this ore con- 

 tains, is combined with lead, it forms an uncommonly 

 beautiful yellow pigment. 



GENCS IX. IRON-ORE. laox-ow. 



Eisen-erz, Moht. 



Tessular, rhomboidal, prismatic. Hardness = 3, 

 6.5. Sp. gr. = 3.8, 5.2. If the streak is brown, the 

 sp. gr. is below 4.2, or above 4.8. If the streak is 

 black, the sp. gr. is above 4.8. 



1. OCTAHEDRAL IRON-ORB. Octaedrisches Eisen- octahedral 

 rz, Moht. Per Oxydule, Hauy. iron-ore. 



Tessular. Cleavage octahedral. Streak black. Hard- 

 ness = 5.5, 6.5. Sp. gr. = 4.8, 5.2. 



This species is divided into two subspecies, viz. 

 Common Magnetic Iron-Ore, and Granular Magnetic 

 I run- Ore. 



FIRST SUBSPECIES. 



COMMON MAGNETIC IRON-ORE, JametOH.Gemeiner Common 

 Magneteiscnstein, Werner. magnetic 



External Character*. Colour iron-black. Occurs iron-ore, 

 massive, disseminated, in distinct concretions, and crys- 

 tallised in octahedrons and rhomboidal dodecahedrons. 

 Externally shining, glistening, or splendent Inter- 

 nally intermediate between shining and glistening, and 

 lustre metallic. Fracture uneven. 



Physical Character!. Highly magnetic, with polarity. 



ContlUuent Part*. Peroxide of Iron, 69 



Protoxide of Iron, 31100 



Berzeliut. 



Geognostic and Geographic Situations. Occurs prin- 

 cipally in beds, in primitive mountains in Norway. 

 Sweden, Lapland, and other countr 



Utet When pure, it affords excellent iron. 

 SECOND Suisricis*. 



GRANULAR MAGNETIC IRON-ORE, or Ioy-SANn, Granular 

 Jameion Eisensand, Werner. magnetic 



External Character*. Colour very dark iron-black. "' 

 Occurs in grains, and also in octahedral crystals. The 

 grains have a feeble glimmering, and rough surface. 

 Internally intermediate between shining and splendent, 

 and lustre imperfect metallic. Fracture conchoidal. 



Geognostic and Geographic Situation*. 'Occurs im- . 

 bedded in trap rocks in different parts of Scotland, and 

 in many countries on the continent of Europe. 



