Alun; 

 . 



Sulphuric Acid, 

 Potash, 

 Water, 



Firoi. 



iur. 



Folisud 



lu or. 



CantiHuent Parlt. 

 Ah 



43.92 

 24.00 

 25.00 



3.08 



4.00 



98.25 

 Klaprulh, 

 Id. s. '256. 



99-00 



I'auquelin. Klaproth Beit, 

 b. iv. s. 252. 



Grognattic and Geographic Siuaiiont. It occurs at 

 Tolfa/near Cirita Vecchia, in nest*, kidneys, and small 

 in a floetz or secondary rock. The Flungarian 

 varieties are found in beds at Btrreg-zaz and Nagy-Be- 

 gany, in the country of Beregher, in Upper Hungary. 

 CM*. Alum is obtained from this mineral, by re- 

 peatedly routing it, then lixiviating it, and crystallizing 

 the solution thus obtained. 



CMC. IV. FLUOH. 



Many axe*. Cleavage octahedral. Hardness = 4.0 

 p. gr. = 3.0, 3.1. 



This genus contains but one species, vis. Octahedral 

 Fluor. 



1. OCTAHEDRAL FLUOH, Jtrmeto*. Flu*, Wenter. 

 Octaedrisches Plus Haloide, Moki. 



Teuular. Cleavage octbedral. Hardness = 40. 

 It is divided into three sul*pecies, Compact Fluor, 

 Foliated Fluor, and Eaithy Fluor. 



FIRST SUBSPECIES. 



COMPACT FLU on, Jometon. Dichter Flus. Wtrntr. 



Eternal Cliaractert. Colour* greeninh-grey, green- 

 ish-white, brownish-red, mountain-prey, and greenish- 

 black. Occurs massive. Externally and internally dull, 

 or feebly glimmering. Fracture ex en, passes on one 



.side into small splintery, on the other into flat con- 



choidal. Fragments rather nharp-edgrd. Mure or lea 



translucent. Brittle, an I eavly frangible. 



Chemical Character!. The chemical characters are 



those .owing subsper 



Geaguottic and Grographif Situation!. It is found in 



vein*, associated with flunr-par, at Slolberg in toe 



Harts. 



SECOND SUBSPECIES. 



FOLIATED FI.UOR, Jameson. Flus-Spath, Werner. 

 Ejt'mnl Character* Most common colour* white, 

 yellow, green and blur, aeldomer red, grey, brown, 

 and least frequently black. Colour* of all degree* of 

 intensity, and sometime* pieces occur spotted or striped. 

 Green cubes occur with blue angles, &c. Some co- 

 lours, as sky-blue, fade by keeping, particularly in 

 warm place*. Occurs massive, disseminated, also in 

 (li-tiiut concretion^ which are large, coarse, small, and 

 fine granular, sometimes straight priomatic, which are 

 traversed by others that are thick and fortification- wi<e 

 curved lamellar. Striped colour delineation in the di- 

 rection of the-<- concretion*. It occurs crystallized, in 

 the following figures: 



1. Cube. -2. Cube, truncated on all the edge*. 3. 

 The rhomboidal or garnet dodecahedron. 4. Cube, 

 with truncated angle*. /!. OcUhedron, or regular 

 double four-sided pyramid. f>. Cube, with bevelled 

 edges. 7. Cube, in which all the angle* are acumina- 

 ted with three planes, which are set on the lateral 

 planes. 8. Cube, in which all the angles are acumina- 

 ted with six planet, which are set on the lateral plane*. 



MINERALOGY. 



Cubes vary from very large, to very small ; the other Oryctogn*. 



crystals are only small and middle sized. Crystals ge- , s - v ' i _ jj 



nerally placed on one another, and form druses ; but are 

 seldom single. Surface smooth and splendent, or dru<y 

 and rough, as in the rhomboidal dodecahedron, anil 

 some octahedrons. Internally the lustre is specular, 

 splendent, or shining and vitreous. Fragments octa- 

 hedral or tetrahedral. Alternates from translucent to 

 transparent, and refracts single. Is brittle, and easily 

 frangible. 



Chemical Character* Before the blowpipe it gene- 

 rally decrepitates, gradually loses its colour and trans- 

 parency, and melts, without addition, into a greyish- 

 white glass. When two fragments are rubbed against 

 each other, they become luminous in the d irk. When 

 gently heated, or laid on glowing coal, it phospho. 

 recces, (particularly the sky-blue, violet-blue, and 

 green varieties,) partly with a blue, partly with a 

 green light. When brought to a red-heat, it is 

 deprived of its phosphorescent property. The violet- 

 blue variety from Nertschinsky, named Chloro/>hane t 

 when placed on glowing coal*, does not decrepitate, 

 but soon throws out beautiful verdigris-green and 

 apple-green light, which gradually disappears as the 

 mineral cools, but may be again excited, if it is heated ; 

 and tlii* may be repeated a dozen of times, provided 

 the heat is not too high. When the chlorophane is 

 exposed to a red-heat, its phosphorescent property is 

 entirely destroyed. Pallas mentions a pale violet blue 

 variety spotted with green, from Cutharinenburg, which 

 is so highly phosphorescent, that when held in the hand 

 far some time, it throws out a pale whitish light ; when 

 placed in boiling water, a green light ; and exposed to 

 a higher tempt rnture, a bright blue light. When -iil- 

 phuric acid is added to heated flour- spar, in the state 

 of powder, a white penetrating vapour (the fluoric acid) 

 is evolved, which has the property of corroding glass. 



CoiulUitenl Parlt. 

 Northumberland. Gcmlorf. Gendorf. 



Lime 

 Fluoric Acid 



67.3 1 



67-75 



65.0 

 35.0 



100.00 100.00 100.0 



Thornton, in Wern. Kliiproth. Beit. Richter, Uber die 



Mi m. vol. i. p. 1 1. b. IT. s. 365. Neuren Ge- 

 gnest. v.Chem b. iv. s. 25. 



GfOgnotlic Situation It occurs principally in veins 

 that traverse primitive, transition, and sometimes Mb 

 comUry rock* ; alto in bed*, associated with other mi. 

 nerals ; in kidneys in secondary limestone ; and in 

 druy cavities in trap-rock". 



Gtofrapkic Situation Kiiropf. Flour-spar is a rare 

 mineral in Scotland, having been hitherto louiul only in 

 four placet, viz. near Monaltree in Aberdeen-lure, 

 where it is contained in a small vein of galena or lead- 

 glance which traverses granite; in gneiss in Sutherland ; 

 in secondary porphyry near the village of Gourock in 

 Renfrewshire; and in the island of Pipa Stour, one of 

 the Shetland islands, in small quantity, in a trip- rock. 

 It occurs much more abundantly in England, being 

 found in all the galena veins that traverse the coal for. 

 mation in Cumberland and Durham ; in great quanti- 

 ties, and often associated with galena, in veins or kid. 

 neys, in secondary or flcetz limestone, in Derbyshire ; 

 and it is the the most common vein-stone in the copper, 

 tin, and lead veins that traverse granite, clay-slate, &c. 

 in Cornwall and Devonshire. 



Utet. On account of the variety and beauty of its 

 colour*, its transparency, the ease with which it can be 



