570 



MINERALOGY. 



Sp. 



ag calcareous-spar, but not so hard as fluor spar. 

 gr. = 3.3. 



Chemical Character!. It easily melts before the 

 blowpipe, with the copious emission of arsenical vapour, 

 and is converted into a reddish-brown mass, which, 

 when highly heated, so as to drive off all the arsenic, 

 becomes attractable by the magnet. These phenomena 

 shew that this mineral is an arseniate of iron, probably 

 combined with manganese. It contains no copper. 



Geognostic and Geographic Situations. Occurs im- 

 bedded in a bed composed of quartz and hornstone, in 

 primitive rocks in the Schneeberg mining district in 

 Saxony ; also at Loling in Carinthia. 



10. SPAK, Jameson and Breithaupt. 



Spak. External Characters Colour white. Occurs in 



small veins, and in thin prismatic distinct concretions. 

 Internally shining and resinous. Has a threefold rec- 

 tangular cleavage. Fracture small-grained uneven, also 

 small splintery. Translucent. Soft, inclining to very 

 soft. Brittle, and easily frangible. Has a feeble sweet- 

 ish saline taste. 



Chem. Characters. It is completely soluble in water. 



Gcognostic and Geographic Situations. Occurs in the 

 salt-mines of Wielickzka and Bochnia in Poland. 



Observations. 1. Its taste is very different from that 

 of common salt, and therefore cannot, like that mineral, 

 be used with food. 2. It is said to be the fibrous rock- 

 salt of Werner. 



11. SPINELLANE, Hauy. 



Spincllane. External Characters. Colour plum-blue. Occurs 

 crystallised, in rhomboids of 117 23', and 62 37' ; 

 and in six-sided prisms acuminated with three planes. 

 Scratches glass. 



Geognostic and Geographic Situations. Occurs on the 

 shores of the Lake of Laach, in a rock composed of 

 grains and small crystals of glassy felspar, quartz, horn- 

 blende, black mica, and magnetic iron-ore. 

 12. BLUE IRONSTONE, Klaproth. 

 External Characters. Colour indigo-blue. Occurs 

 massive, and with impressions of crystals of brown 

 iron-ore. Externally glimmering, internally dull. 

 Fracture coarse-grained uneven. Opaque. Semihard. 

 Rather brittle, and easily frangible. Specific gravity 

 3.20, Klaproth. 



ChemicalCharacters.-- Loses colouron exposure toheat, 

 and when melted with borax, forms a clear green bead; 

 Constit. Parts. Oxide of Iron, . 40.5 

 Silica, . . 50.0 

 Lime, . . 1.5 

 Natron, . C.O 



Water, . . 3 0100.0 

 Geographic Situation. It occurs on the Orange River 

 in Southern Africa. 



Uses. It is used for painting houses at the Cape of 

 Good Hope. 



Chusite, Limbillite, Sideroclepte, Mellilite, and 

 Succinite, minerals described by Saussure and Bonvoi- 

 sin, appear to be varieties of Olivine and Augite. 



MINERALS OF THIRD CLASS. 



Argcntife- 13. ARGENTIFEROUS COPPER-GLANCE, Jameson. 



rouscop- Silber Kuperfer-glanz, Hausmann. 



per glance. External Characters. Colour blackish lead-grey. 

 Occurs massive and disseminated. Internally shining 

 or glistening, and lustre metallic. Fracture flat con- 



Blue iron- 

 tone. 



rjj 8mul h 

 silver. 



choidal, passing into even. It becomes more shining Append!: 

 in the streak, but the colour is not changed. As ""'V" 

 hard as calc-spar. Sectile, and rather difficultly fran- 

 gible. Specific gravity C.255, Slromcyer. 

 Conslit. Parts. Sulphuret of Copper, 88654 

 Sulphuret of Silver, 60.646 

 Sulphuret of Iron, 0.700 100 

 Slromcyer. 



Geognostic and Geographic Situations. This rare mi- 

 neral is found only at Schlangenberg in Siberia, where 

 it is associated with copper-pyrites, calcareous-spar, and 

 hornstone. 



14. BISMUTHIC SILVER, Jameson. 



External Characters. Colour pale lead-grey, be- 



coming deeper on exposure to the air. Occurs disse- 



minated ; and rarely crystallized in acicular and capil- 



lary crystals. Lustre glistening and metallic. Frac- 



ture fine-grained uneven. Soft. Sectile. 



Constit. Parts. Bismuth, . 27.00 



Lead, . . 33.00 



Silver, . 15-00 



Iron, . 4-30 



Copper, . 0.90 



Sulphur, . 16.3096.50. 



Klaproth, Beit. b. ii. s. 297. 



Geognostic and Geographic Situations. It has hither- 

 to been found only in the mine named Friedrich-Chris- 

 tian in the Schapbach, in the Black Forest, where it 

 occurs in veins that traverse gneiss, along with copper- 

 pyrites, quartz, iron-pyrites, and galena or lead-glance. 



15. NATIVE NICKEL, Jameson. Haarkies, Werner, j^j,,. 

 Nickel Natif, Haitij. nickel" 



Observation. It is the Haarkies of Werner. 

 External Characters. Colour kind of brass-yellow, 

 which inclines to bronze-yellow, and seklomer to steel- 

 grey. Occurs in delicate capillary crystals. Shining or 

 glistening, and lustre metallic. Crystals rigid. Brittle. 

 Const. Parts It consists, according to Klaproth, of 

 Nickel, with a small quantity of cobalt and arsenic. 



Geognostic and Geographic Situations. It occurs in 

 veins in gneiss, where it is associated with hornstone, 

 quartz, calcareous-spar, and brown-spar, at Johangeor- 

 genstadt in Saxony; also in the cavities of copper nick- 

 el in Huel Chance Mine, near St. Austle in Cornwall. 



16. PYROSMALITE, Jameson. 



External Characters. Colour liver-brown, inclining p yr0 sma 

 to pistachio-green. Occurs in straight lamellar con- lite. 

 cretions, and crystallized in regular six-sided prisms. 

 The most distinct cleavage is parallel with the ter. 

 minal planes of the prism ; another less distinct parallel 

 with the lateral planes of the prism. Fracture uneven, 

 passing into splintery. Internally lustre of cleavage 

 shining and pearly. Fracture glimmering. Translu- 

 cent on the edges. Semi-hard. Streak brownish-white. 

 Brittle. Specific gravity, 3.08 1 . 



Constit. Paris. Protoxide of Iron, . 21.810 

 Protoxide of Manganese, 21.140 

 Submuriate of Iron, . 14.095 

 Silica, . . . S5.850 

 Lime, . . 1.210 



Water, and Loss, . . 5.895 

 Hisitiger. 



Geognoslic and Geographic Situations. It occurs in a 

 bed of magnetic ironstone, along with calcareous-spar 

 and hornblende, in Bjelke's mine in Nordmark, near 

 Philipstadt in Wermeland. 





