130 EARTHS, argillaceous. 38. Mica. 
Found in Bohemia near heidfchux, Lam, and Lohofan, i" 
Wajfovia near Datweiler, in Hungary on mount Schater, pO' 
rous orcompaft, more or lefs pondtrouj, of a reddifh, citiC' 
reouj, black, blue, iron, fteel or iridefcenc colour. 
38, MICA. Confiding of filica and alumina, witf* 
a finall proportion of oxjdeof iron, and gene- 
rally a little magnefia and lime ; glabrous, mea- 
gre, fiiining, fpoiitaneoully falling into granulaf 
fragments, eafily breaking into difcoid fragmentSr 
lightifir, parafitical: fufible before the blow-pip® 
into a white or coloured enamel. 
membrana- Tranfparent, with large parallel elahic eafily feparabl®^ 
plates. 
Mica membranacea. Syft. nat, xii 3./. 58. ». i. 
Mica membranacea. Walk Jyst. mitt, i . p. 369. «. i . 
Mica, Mufeovy talc. Kirnvan mineral. \,p,2lO, 
Mica, Glift. Sehmelfser miner, i. p. 176. 
Mica. Thom fan them. 3 539. 
Found in Malabar, Siberia, BuJJia, Finland, France, and 
Geneva, in large plates which are often fubllituted for glal*' 
and confifts of a great number of thin tranfparent lamin® 
hering together: thefe are readily diftinguilhed from tl'® 
layers of Gypfum fpcculare and glaciate, from their gre*' 
degree of flexibility ; texture foliated : fragments flat : luftt* 
metallic: very tough; often abforbs water : feels finiiotl’’ 
but not greafy : fpecific gravity from 2,6546. to 2,934®' 
contains filica 50,00. alumina 35,00. oxyde of iron 7>o°’ 
magnefia 1,35. lime 1,53. Vauquelin. 
laminosa. Tranfparent, coloured, with large parallel eafily fepar®' 
bie plates 
Mica membr. fiflilis. Spt. nat. xii. 3. p. 5.8. ». 2. 
Mica merabran. femipelluc. Wall. fill. \ .p. 369. n. 2. ' 
Found principally in the granites of primeval mountains, g®' 
nerally fmoke-colour or black, frmetimes brown, gold, re“' 
or white, and very rarely concreted in malTes refembli'’® 
pieces of Shale. 
squamosa. Somewhat opake, with lefTer fcattered incurved foliations- 
1. Of a filvery colour. 
Mica fquamofa argentea, Syst. nat, xii. 3. p. 58 ». 3,. 
2. Ol a gold colour. 
Mica iquamola aurata. Syst, nat. xii, 3, p. j8, ». 4. 
