EARTHS. ARGILLACEOUS. 41. Scorfus, 139 



41 » SCORLL'S. Confining of alumina and filica, 

 nioftiy oxyde of iron, with frequently a little 

 carbonate of fnagntlia and oxyde of manganele: 

 hard, breaking into indeterminate fragments, 

 iliining internally, parafiticah not efFervefcing 

 with nitric acid, and eafily melting into a glafs. 



grdnmima^ White, Iiardilli, fufible in the tire with fome difficulty, 

 cafilv nioulderini;. 



Graniti vianehi. Gi'-vnui ktolog. Vefurj. p. 38. 



Bergman deptod. 'v^lcatu opufc. 'vol. 3. />• 2c6, 

 "^ Shorl, Bafaltine, White Garnets. KiKwan \. p, 285. 426. 



Volcanic S ho rl. Schmei/ier miner. 1.^.85. 



Leucite. ThofKfon chefn. i./». 552. 



Found in the Lavas v>i Vefwviusy where it appear?, according to 

 Kir-wan^ to have pre-exiflcd in the rocks which were the 

 morhcr liones or bafis of lavas before the eruption, and is not 

 formed by fubfcquent percolation through, and cryftallization 

 ■* in !heme!ted lava : colour white or greyifis-white : it is al- 



ways found in cryllals, the pvimitiye form of which are ei- 

 ther cubes or rhoinboidal dodecahedrons : texture foliated : 

 fra£lure more orlefs conchoidal :: it is fometimes tranfparent, 

 hut opake when decompofing : its powder caufes fyrup of 

 violets to alTaHie a green colour: is hardly fufible before the 

 blowpipe, and gives a white tranfparent glais with borax : 

 ipeciric gravity from 2,455. ^^ 2.490. contains iilica 54. 

 alumina 23, potafs 22. iron o. Klaproth. 



fviirms^ Brittle, fliining, of a minutely conchoidal texture, eafily 

 niehiiig before the blowpipe with froth into a hard 

 black enamel. 



Thumeriloi^e. Kirnvaft miner, i. ^. 273. 



Thumerilone, Purple brown Schorl, ^chmeijfcr 1./, 86. 



Thummerftone. Thottifon chem, 3. p* 596. 



I, Of a common form, diaphanous or fubopake, fpontaneouily 

 falling into cruilofe fragments. 



2.. In very fhining pellucid or femipeflucid cryftals which arc 

 fomev.hat prifmatic, with rhomhoidal faces, generally ftriatcd 

 longitudinally. 

 Found near Thervi and Schneehurg in Saxony, near Bourg de 

 Oi/ans in Dauphinei in the Pjrenean mountains, and in- 

 I^orvjay near Kongiburg : colour clove-brown, fometimes 

 inclining to red, green, grey, violet or black : ii generally 

 found in cry ftals, the moil ufual of which are flat rhomhoidal 

 parallelopipeds with the oppofue edges a little truncated ; the 



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