EARTHS. SILICEOUS. 44. FeldfpatiniT. 



151 



In S-fided right angles. 

 In 4-rided oblique angles. 

 In 6-fided oblique angles. 



Found every where in primrtive mountains, forming a part of 

 Granite, Porphyry and Gneifs rocks, compact, f.-lid, and in- 

 corporated with other fubftances ; and generally moulders 

 into a kind of porcelane clay: colour generally flefh colour, 

 bluei(h-grey, yeliowifh-whire, milk-white or brownifli-yel- 

 low, rarely blue or olive green, Very rarely black: ttxturc 

 in ;ftraight (hining foliations, crofs fra (flu re uneven ; when 

 heated, the cryllailized kind often decrepidates : it is lefs 

 hard than Quartz, but ftrikcs fire with fteel : fpecific gravity 

 from 2,272. to 2,594. contains filica 62,83. alumina 17,02. 

 pota Is 16,00. lime 3,00. oxyde of iron 1,00. Vuuqueltn. 



cvarialik. Of a vivacious luftre, reftedling various colours in certair> 

 poiitions of light, of a foliated texture, breaking in- 

 to rhomboidal fragments with 4 fpecular faces, 

 Labradorftein. Lejk. Naturf. 12. p. 145'. 

 Labradore ftone. Kirnuan mineraL l.p, 3?4, 

 Labradore Fellpar. T/jom/on chem, ^. p, ^^^, 

 Labrador Hone. SchmeiJ/er mineral, i, p. 17,/^. 

 Found on the Labradore coajlt the ifland St.PauPsi in various 

 parts of America and Europe, in round mafles and detached, 

 and often containing Scorl, Mica, and Pyrites : colour 

 dark or light grey, diaphanous or femipellucid, receiving a 

 high polifh, and reflecting various colours of blue, purple, 

 red, green, &c. in certam pofitions, in fpots or itripes : 

 fpecific gravity from 2,6700. to 2,6925. 



limare. Pellucid, vi^hite, of a high luftre, and flralght lamellar 

 texture, breaking into rhomboidal fragments. 



Moon -ftone. Kir^wan, mineral. 1. p. ^zz. ^ 



Moonftone, SchmeiJJer mitu i. p. 136. 



Pure Felfpar. Thomfon chetn. 3. p. 555, 



Found in Ceylon and Sivitzeriandy Bohemia and Saxony^ in folid 

 mafies and alio cryftallized ; the cryftals rhomboidal, of irre- 

 gular angular broad 6-fided columris terminating in pyramids 

 and in rettangular 4-fidcd plates : colour white, with fome- 

 times a Ihade of yellow, green or red, the ii^rface often re- 

 fleding-iridefcent- colours: the fragments often appear ftri- 



. ated : fpecific gravity 2,559. contains fiiica 64. alumina 20. 

 potafs 14: lime 2. rauquelin* 



fibroium* Fibrous, v^^ith the fibres parallel and in diftin£l layers. 



Ltndackeo ap. J. Mayer SammU Phyf,Auff. 2 p. 278. 



Found fcattercdly in Bohemia^ with frequently the veftiges of 

 quartz or mica ; colour ufually brown : fhining internaily 

 like mother of pearl, breaking into indeterminate fragments, 

 and is harder than rock-cryilal. 



