MINERALOGY. 



Geme'mer magnetjlein, Werner. This ore is highly magnetic 

 with polarity. According to Berzelius, it contains 



Peroxyd of iron ... 71.86 



Protoxyd of iron ... 28.14 



100 



It occurs in various parts of the world, chiefly in primitive 

 mountains ; it is found at St. Juft in Cornwall, and Tavif- 

 tock in Devonfhire. 



Iron-fand, or Sandy Magnetic Iron-Jlune, Fer oxyduU 

 titanifere, Haiiy, (fee Irox-ore,) occurs in volcanic 

 and bafaltic rocks, forming a component part of many 

 black lavas, and in the fands of rivers. According to Cor- 

 dier, its conftituent parts are, 



Earthy Magnetic Iron-Jlone ; Fer oxyduU fuligineux, 

 Haiiy ; OBriger magneteifenjlein, Werner. — The colour is 

 blueifh-black ; it is opaque, foft, feftile, and eafily frangi- 

 ble. It appears to be common magnetic iron-ftone in a 

 ftate of decompofition. Common magnetic iron-ftone and 

 iron-fand are diftinguifhed from iron-glance by the colour of 

 the ftreak, which is black ; but that of iron-glance is red. 

 According to Mr. Jamefon, Werner was tlie firil who ob- 

 fer%'ed that magnetic iron-ftone does not poffefs the magnetic 

 property when at a depth in the eartli, but it acquires it 

 after expofure to the atmofphere. 



Specular Iron-ore, or Common Iron Glance; Fer oligijle, 

 Haiiy ; Eifenglanz, Werner This ore, according to dif- 

 ferent analyfes, appears to contain about 90 per cent, of 

 oxyd of iron. See Irox-ores. 



Scaly Red Iron-ore, or Iron Froth; Fer oligljle rouge 

 luifant, Haiiy ; Rother eifenrahm. Ochry Red Iron- 

 Jlone ; Fer oxyde rouge grojfter ; Ochriger rotherfenjlein, 

 Werner. 



Compact Red Iron-Jlone ; Fer oligijle compade, Haiiy ; 

 Dichter rotherfenjlein, Werner. 



Red Hematite, or Fibrous Red Iron-Jlone; Fer oligijle 

 concretione, Haiiy ; Rother glafskopf, Werner. See Iron- 

 ores. 



Scaly Brown Iron-ore ; Brauner eifenrahm, Werner. 

 Ochry Brown Iron Jl one ; Fer oxyde pulverulent, Haiiy. 

 Compa3 Brown Iron-Jlone ; Fer oxyde brun compaHe, Fr. ; 

 Dichter braun eifenjlein, Werner. Brown Hematite; Fer 

 ■exyde hemaiite brun, Haiiy ; Brauner glafskopf, Werner. 

 -^Brown iron-ftone is diftinguiftied from red iron.ftone by 



its red ftreak and inferior fpecitlc gravity : it alfo contains 

 more water, the brown u-on-ftone being an hydrate. This 

 ore, according to profeflbr Jamefon, makes but indifferent 

 caft-iron, but affords good malleable iron and excellent fteel. 

 See Irox-ore. 



Compaa Black Iron-Jlone ; Dichter fwarzeijfenjlein. Black 

 hematite; Mine de fer noire compaBe, Fr. ; Schwarzer 



glafskopf, Werner When melted with borax before the 



blow-pipe, it yields a violet-blue glafs ; hence it is conjec- 

 tured to contain much manganefe. 



Sparry Iron-Jlone ; Cbaux carhonatee ferrifere aver man- 

 ganefe, Haiiy. 



Clay Iron-Jlone; Fer oxyde majf Haiiy; Thoneifonjlein, 

 Werner. See Irox-ore, and Clay Irm-Jlone, Addenda. 



Reddle; Argile ocreuje rouge graphique, Haiiy; Roethel, 

 Werner. 



Columnar Clay Iron-Jlone ; Fer argilleux bacillaire, Fr. 

 Lenticular Clay Ironjlone ; Fer oxyde brun granuleux ou 

 lenticulaire, Fr. (See Irox-ore.) — The following analy- 

 fis of this ore is given by Daubuiflbn, Journal des Mines 

 1810. 



Peroxyd of iron 



Water - - . . . 



Silex ..... 



Peroxyd of manganefe 



Lofs - - - . . 



73 



9 

 I 



3 



Jafpery Clay Iron-Jlone. See Irox-ore. 



Reniform Clay Ironjlone; Fer oxyde geodique, Haiiy. 



The conftituent parts of this ore are ftated by Daubuiflbn. 



Peroxyd of iron 



Water 



Silex . - - 



Oxyd of manganefe 



Alumine ... 



97 



99 



See Iron-ore. 



Pea-ore, or Pifeform Iron-ore; Fer oxyde globuliforme, 

 Haiiy ; Bohnerz,, Werner. See Irox-ore. 



Bog Iron-ore. See Irox-ore, and Bog Iron-ore, 

 Addenda. 



Pitchy Iron-ore; Fer oxyde rejinite. — The pitchy iron 

 defcribed under the article Irox-ores appears to be a phof- 

 phate of iron : later mineralogifts defcribe it as an oxyd 

 and fulphate of iron. It is a rare ore, having been found 

 only in one mine near Freyberg, and in the diftrici of Plifs 

 in LFpper Silefia. Its colour is grepfli-black, paffing into 

 dark liver-brown. It is faid to occur forming crufts. It 

 has a fplendent or fhining refinous luftre. The fraiSure is 

 imperfeftly conchoidal : it is compofed of granular diilinft 

 concretions : it is tranflucent on the edges : the ftreak is 

 lemon-yellow : it is foft. When placed in water, it becomes 

 femitranfparent and vitreous. According to Klaproth, its 

 conftituent parts are, 



Oxyd of iron ... 67 

 Sulphuric acid ... 8 



Water 20 



95 



Blue Iron-ore ; Blue Iron Earth ; Fer phofphate terreutc, 



Hauy. 



