MINERALOGY 



485 



This Subspecies is divided into two Kind*, fix. 

 Common Phosphorite and Earthy Phosphorite. 



First Kind. 



COMMON PHOSPHORITE, Jameson. Gemeiner Phos- 

 phorit, Kinten. 



External Character! Colour yellowish-white, some- 

 times approaching to greyish-white. Occasionally spot- 

 ted pale ochre-yellow, and yellowish-brown. Occurs 

 mauive, and in distinct concretions, which are thin 

 and curved lamellar. Surface uneven and drusy. 

 Dull or glistening. Cleavage imperfect curved, and 

 generally floriform. Fracture uneven. Fragments in- 

 determinate angular, and rather blunt-edged. Opaque, 

 or feebly translucent on the edges. 



Chemical Character! It becomes white before the 

 blowpipe, and, according to Proust, melts with dim- 

 culty into a white-coloured glass. When rubbed in an 

 iron mortar, it emit* a green-coloured phosphoric light ; 

 and the tame effect is produced when it is pounded 

 and thrown on glowing coaU. 



Coiitiiluent I'arlt Lime, . 59.0 



Phosphoric Acid, 31.0 

 Silica, . 20 



Fluoric Acid, 

 Muriatic Acid, 0.5 



Carbonic Acid, 1.0 



Oxide of Iron, 1.0100.0 



Pelletier, Journal de Mines, N. 166. 

 Ctognottic and Geographic Situationt It occurs in 

 crusts, and crystallized, along with apatite and quartz, 

 at Schlackenwald in Itohemia, but most abundantly 

 near Leigroaan, in the province of Estretnadura in 

 Spain, where it is sometime* associated with apatite, 

 ami forms whole beds, that alternate with limestone 

 and quartz. 



Second Kind. 



EARTHY PHOSPHORITE, Jameton. Enliger Phos- 

 phorit, Kariten. 



'ernal Character* Colours greyish- white, green- 

 ish-white, and pale greenish-grey. Consists of dull 

 duty particles, which are partly loose, partly cohering, 

 and which soil slightly, and feel meagre and rough. 



Chemical Character*. It phosphoresces when laid 

 on glowing coals. 



I".rth jr Fhoipborite from Mumanxch. 

 Coiuttluent Parts.- Lime, . 47-00 



Phosphoric Acid, 32.25 

 Fluoric Acid, 2.50 



Silica, . 0.50 



Oxide of Iron, 0.75 



Water, . 1.00 



fixture of Quartz 



and Loam, 11.50-95.50 



Klaproth, Beit. b. iv. a. S?3. 



Ctognoilic and Geographic Situation* It occurs in. 

 vein, in the district of Marraarosch in Hungary. 



GEKUJ VI. LIMESTONE. 



Kalk.Haloi.li-. UoJb. 



One and three axes. Cleavage di-prismatic ; rhom- 

 boidal. Hardness ranges from 3.0 to 4.5. Sp. gr. = 

 25 32. 



Tlii* gomn contains four specie*, viz. 1. Prismatic 

 or Arragonite. 2. Khomboidal or calcareous spar. 3. 

 Short axed, including dolomite and several varieties of 

 rhnnl'-ipar. 4. Long axed. Rhomb-spar in part. 



I- PRISMATIC LIMESTONE, or ARHAGONITE, Jame- 

 . JM> PrUmatiichcr Kalk-Haloidc, Mohi. Arragon, 

 Werner. 



Vertical prism = 115 56' ; horizontal prism in the Oryctog no- 

 direction of the shorter diagonal 109 28'. The cleav- ^-, 

 age is the same, but most distinct in the direction of " 

 the smaller diagonal of the vertical prism. Hardness 

 = S.5, 4.0. Sp. gr. = 26, 3.0. 



This species is divided into two subspecies, via. 

 Common Arragonite, and Coralloidal Arragonite. 



FIRST SUBSPECIES. 



COMMON ARRAGONITE, Jameson. Gemeiner Arra- Common 

 gon, Werner. Arr.ge- 



Exlernal Character!. Colours white, grey, green, 

 and violet-blue. In some crystals, green and blue 

 colours occur together, and sometimes also grey. Oc- 

 curs massive, and in distinct concretions, which are 

 thick, thin, and very thin prismatic, and sometimes 

 scopiformly diverging. It is frequently crystallized. 



The following are some of its secondary figures : 

 1. Irregular six-sided prism, frequently with four late- 

 ral edges of about 116, and two of 128; or with 

 three lateral edges of 128, two of 1 16, and one of 

 1O4. These are formed by the grouping of several 

 oblique four-sided prisms, bevelled on the extremi- 

 ties. Sometimes this prism is so flat, that it appear* 

 like a table. 

 8. Six-sided table. 



When, on the contrary, the long six-sided 

 prism becomes acicular, there is formed 

 8. Long, and generally acicular double six-sided pyra- 

 mid-. 



The crystals are middle-sized and small ; they are 

 generally attached by their terminal planes, seldomer 

 l>y their lateral planes ; sometimes imbedded, and are 

 to be observed intersecting each other. Lateral planes 

 of the crystals sometimes smooth, more frequently more 

 or less deeply streaked or grooved. Terminal planes 

 seldom smooth, generally uneven and rough, and some- 

 times also deeply notched. External lustre varies from 

 dull to shining, and is vitreous : internally shining and 

 glistening, and vitreous, inclining to resinous. Frac- 

 ture small snd imperfect conchoidal, passing into un- 

 even. Fragments indeterminate angular, and rather 

 sharp-edged ; in the prismatic varieties splintery. 

 Translucent, passing into semi-transparent, and re- 

 fracts double. Brittle, and easily frangible. 



Chemical Charactert If we expose a small fragment 



to the flame of a candle, it almost immediately splits 

 into white particles, which are dispersed around the 

 flame. This change takes place principally with frag- 

 ments of transparent crystals, fragments of the other 

 varieties becoming merely white and friable. Frag- 

 ments of calcareous-spar, when placed in a similar situ- 

 ation, undergo no alteration. Completely soluble, with 

 effervescence, in the nitric and muriatic acids. 



Comtitucnt Parti. 



From Molina ID Amgon. 

 Carbonate of Lime, 9*,5757 



Carbonate of Strontian, 3-9662 

 Hydrate of Iron, - 0.7060; 



Wator of Crystallization, 0.3000- 99.54-89 



Stromeyer, in Gilbert's Annalen der Physik, xiv. 217. 



October, 1813. 



Geognotlic and Geographic Situations Evrojx. It 

 occurs along with galena in the lead mines of Lead- 

 liills, and in secondary trap-rocks in different parts of 

 Scotland. It is one of the many interesting mineral* 

 met with in the secondary trap-rocks of the island of 

 Iceland, and in the trap-rocks of the Department of 

 the Puy de Dome, of Caupenne near Dax, and at . . 



