MINERALOGY. 



Orrctogno. serpentine in the wine Tschistagowskoy, on the ri- 

 ver Mjal's, in the Government ul Urenberg in Russia. 



/ hint Kind. 



Compact COMPACT DOLOMITE, or GURHOFITE, Jameson. 

 Dolomite. Gurholiai), Kanttm. 



Ejct'mat Characters. Colour snow-white. Occurs 

 ma**ive Dull. Fracture flat conchoidal, passing to 

 even. Fragments indeterminate angular, and sharp- 

 edged. Slightly translucent on the edges. Hard, 

 bordering on seuihard. Brittle, and rather difficultly 

 frangible. 



C'-nur./jl Character*. When pounded, and thrown 

 into diluted and heated nitrous acid, it is completely 

 dissolved, with effervescence. 



Const. Parlt Carbonate of Lime, 70.5O 



Carbonate of Magnesia, 59.50100 00 

 Ktuproth, Gesellsch. N. Fr. b. i. s. 858. 



Geognottic and Geographic Situations It occurs in 

 \(im in serpentine rocks, between Gurhof and Aggs- 

 bach, in Lower Austria. 



SECOND SUBSPECII*. 

 MitwUe. MIEMITE, Jameson and klijtroth. 



This ubpecie* is divided into two kind*, viz Gra- 



Granular 

 Mienme. 



nular Miemite, and Prismatic Miemite. 



First Kind. 

 GRANULAR MIEMITE. 



External Character! Colour pale asparagus-green 

 which passes into greenish-white. Occurs massive, in 

 large and coarse angulo-gramilar distinct concretions ; 

 crystallized in flat double three-sided pyramids, in 

 which the lateral planes of the one are set on the lateral 

 edges of the other. Crystals middle-sized, or small ; 

 either attached by their lateral edges, or intersecting 

 each other ; surface drusy. Internally splendent and 

 pearly. Fragments rather blunt-edged. Translucent 

 Semi hard. Brittle. Specific gravity 2.885. 



Contiit. Parts. Carbonate of Lime, 53.00 



Carbonate of Magnesia, 48. 50 

 Carbonate of Iron, with a 

 little Manganese, 3.00 



98.50 



Klaproth, Beit. b. iii. s. 896. 



Geognottic and Geographic Situations. It is found 

 at Miemo in Tuscany, imbedded in gypsum. 



Oojenation* This mineral was first observed by 

 the late Dr Thomson of Naples, who sent specimens 

 of it to Klaproth for analysis. It is named Miemite, 

 after the place where it was discovered. 



Second Kind. 



PHMMATIC MIEMITE, Jameson. Stanglicher Bitters- 

 ' 



Mictime. 



External Characteri. Colour asparagus-green, olive- 

 green, and oil-green. Occurs in prismatic distinct 

 concretions, and crystallized in flat rhomboids, which 

 are deeply truncated on all the edges. Crystals small, 

 and very small, and sometimes they form only drusy 

 crusts. Internally shining and vitreous. Fracture 

 panes from concealed foliated to splintery. Frag- 

 ments rather blunt-edged. Strongly translucent. As 

 hard as the granular ruiemite. Specific gravity, 2.885, 

 Kartlcn. 



Chemical Characlert. It dissolves slowly, and with 

 but feeble effervescence, in nitrous acid. 



VOL. XJT. PART n. 



Constituent Paris. Lime, 



Magnesia, 

 Oxide of Iron, 

 Carbonic Acid, 

 Water and Loss, 



Klaproth, Beit b. iii. s. 303. 



Geognoslic and Geographic Situations. It occurs in 

 cobalt veins that traverse sandstone at Gliicksbrunn in 

 Gotha, and at Beska in Servia, on the frontier of 

 Turkey. 



THIRD SUBSPECIES. 



or PEARL-SPAR, Jameson. Braune- Brown- 



spar, or 

 pearl-spar. 



path, Werner. 



This species is divided into two kinds, viz. Foliated 

 Brown-Spar, and Columnar Brown-Spar. 



First Kind. 



FOLIATED BROWN-SPAR, Jameson. Blattriger Braun- Foliated 

 spath, Werner. brown-ipar. 



External Characters. Colours flesh-red and brown- 

 ish-red. Often occurs massive, also disseminated, sel- 

 dom globular, stalactitic, reniform, with tabular and 

 pyramidal impressions ; also in distinct concretions, 

 which are granular, and rarely thin and straight la- 

 mellar ; and frequently crystallized. Surface of the 

 crystals usually drusy, and seldom shining, generally 

 glistening or glimmering, and sometimes even dull. 

 Internally alternates from shining to glistening, very 

 rarely splendent, and lustre pearly. Fragments inde- 

 terminate angular, and rather blunt-edged in the great, 

 but in the small are rhomboidal. Generally translu- 

 cent on the edges, rarely translucent. Brittle, and 

 easily frangible. Specific gravity, 3.0, 3.2, Muks. 



Chemical Characters. It hardens, and becomes dark 

 brownish-black before the blowpipe ; and effervesces 

 feebly with acids. 



Constituent Parts. Lime, . . 43.0 



Magnesia, . 10.0 



Oxide of Iron, . 8.0 



Manganese, . 3.0 



Water, and Carbonic Acid, 26.5 



Berthier, Journ. des Mines, No. 103. p. 73. 



Geographic Situation. It occurs, along with galena, 



and other ores of lead, in the lead mines of Lead Hills 



and Wanlockhead in Lanarkshire; in the mines of 



Cumberland, Northumberland, and Derbyshire. 



Second Kind. 



COLUMNAR BROWN-SPAR, Jameson. 

 Braunspath, Klaproth. 



Stanglicher Columnar 

 brown par. 



External Characters. Colours reddish-white, rose- 

 red, and pearl-grey. Occurs in distinct concretions, 

 which are wedge-shaped columnar or prismatic, and 

 have glimmering and longitudinally streaked surfaces. 

 Splendent, and appears pearly on the fracture-surface. 

 Has an imperfect cleavage. Fragments wedge-shaped. 

 Translucent. Brittle. Easily frangible. 

 Conttit. Parlt. Carbonate of Lime, 51.50 



Carbonate of Magnesia, 32.00 

 Carbonate of Iron, 7.50 



Carbonate of Manganese, 2.00 

 Water, . . 5.00 



98.00 



Klaproth, Beit. b. iv. s. 203. 

 3 B 



