1034 IRON MINERALS 



Iron of all kinds produced in the German Customs Union. 



centners Iba. avoirdupois 



1866 . . . 110,231 . . . 20,933,070 



1867 ... ... 22,272,126 



1868 25,286,944 



1869 28,260,518 



1870 ... 27,822,471 



IRON-BARB! TREES. Certain species of Eucalyptus, valued for their wood, 

 are so called in Australia. 



XROX LIQUOR. A solution of acetate of iron, used as a mordant by calico- 

 printers. 



IRON, METEORIC. See AEROLITES. 



XROX IVIXXERAXiS not used as Ores : 



1. Iron- Alum or Halotrichite. A sulphate of alumina and sulphate of iron, with 

 43 per cent, of water. Occurs in fibrous silky masses of a yellow colour. It is found 

 in the exhausted beds of Hurlet and Campsie, near Paisley. It occurs in Persia, 

 where it is used for making ink ; and in Bhenish Bavaria. 



2. Iron- Apatite or Zwieselite. A phosphate of iron and manganese. See ZWIE- 



SELITE. 



3. Iron, Arsenate of; Pharmacosiderite ; Wurfelerz. This mineral, which is rather 

 rare, occurs in great beauty associated with copper-ores in Cornwall ; it has an olive- 

 green colour, and is rather brittle. Its composition, according to the analysis of 

 Berzelius, is : arsenic acid, 40*4.; peroxide of iron, 28*1; protoxide of iron, 12'6 ; 

 water, 18 '9. 



4. Iron, Chr ornate of; Octohedral Chrome-ore ; Chromite. This mineral occurs in 

 serpentine, or in crystalline limestone, near this rock. It was first discovered at Gassin, 

 in the Var department in France, and is found in Saxony, Silesia, Bohemia, and 

 Styria ; also in Norway ; and in large masses in the Ural, near Katharinenberg. It has 

 been found also in great abundance in Unst and Fetlar, in the Zetlands ; the mineral 

 is opaque, with a semi -metallic lustre ; colour, iron or brownish-black, streak yellowish 

 to reddish-brown. A specimen from Norway, analysed by Von Kobell, gave protoxide 

 of iron, 25*66 ; sesquioxide of chromium, 54'08 ; alumina, 9'02 ; magnesia, 5*36 ; and 

 silica, 4'83 : another specimen, from Chester in Pennsylvania, yielded to Sebert prot- 

 oxide of iron, 36-00 ; oxide of chromium, 39-61 ; alumina, 13'0 ; and silica, 10-60. It is 

 used in the preparation of various pigments. For the treatment and use of the ore, 

 see CHROME. 



5. Iron-Chrysolite or Fayalite. An anhydrous silicate of iron, in which iron is 

 replaced by manganese. It is found in the Mourne mountains. 



6. Iron-Flint. A quartz containing 5 per cent, of oxide of iron. It is found in 

 St. Just and Marazion in Cornwall. 



7. Iron-Natrolite.^-A. variety of natrolite, in which one-fourth of the alumina is 

 replaced by peroxide of iron. See NATROLITE. 



8. Iron, Oxalate of ; Oxalite; Humboldtine. This mineral, which occurs in the form 

 of capillary crystals in the brown coal at Kolosoruk, near Bilin, in Bohemia, and at 

 Gross Almerode in Hessia, is composed, according to the analysis of Eammelsberg, of 

 oxalic acid, 42-40; protoxide of iron, 41*13; and water, 16'47. 



9. Iron, Phosphate of; Slue Iron ; Vivianite. The colour of this mineral varies 

 from indigo-blue to blackish green ; the earthy variety is white in the beds, but 

 changes blue on exposure to the air; heated in a closed tube it yields much water, in- 

 tumesces, and becomes spotted with grey and red ; before the blowpipe on charcoal, it 

 fuses to a grey, shining, metallic granule. Transparent indigo-coloured crystals of 

 phosphate of iron, sometimes an inch in diameter and two inches long, occur, with iron 

 and copper pyrites, in the tin and copper veins at St. Agnes in Cornwall. It was first 

 found in the auriferous veins at Vorospatak in Transylvania ; the earthy varieties are 

 very common in Cornwall, Styria, North America, Greenland, and New Zealand. 

 A specimen from St. Agnes, Cornwall, gave Stromeyer phosphoric acid, 31*18; prot- 

 oxide of iron, 41*23 ; water, 27'48: and another from New Jersey yielded to Kam- 

 melsberg phosphoric acid, 28'40 ; protoxide of iron, 33'91 ; peroxide of iron, 12-06. 

 It is sometimes used as a pigment, but is of no use as a smelting ore. 



10. Iron, Pitchy Hydrate of ; Pitticite ; Eiscn&inter. This mineral occurs in many 

 old mines, especially .those near Freiberg; and also at Schneoberg in Saxony, PI< -iss 

 in Silesia, and Bleistadt in Bohemia. It is probably a product of the decomposition 

 of mispickel : its composition, according to the analysis by Stromoyer, being Fe'-'O 3 , As 

 O 5 + Fe 2 O s ,SO s + 15HO = 35 peroxide of iron, 26 arsenic acid, 9 sulphuric acid, and 

 30 water. According to Freiesleben, it is first fluid, and gradually separates in a solid 



