EARTHS. ARGILLACEOUS. 35.Arderia. 
125 
4. Kolon. Cromt. mimral. jeft. \i'&. 
Found in Britain, ^•vicden, and Lusatia, forming large bed? in 
llralified mountains, and is ftrongly impregnated with i itu- 
men and fulplnir pyrites; colour generally hlick, a little 
glittering when broken: when expofed to heat it fmokes or 
flames, emits a bituminous odour, and becomes paler Stter 
lofirg its bitniTicn. 
Kellas. Of a fibrous texture, flightly adhering to the tongue. 
Killas. Kir’wan niinerai. 1 . p. “ 37 ‘ 
Found in Coi-x’wall, of a pale blueilh-grey, red, or vvhitHli, 
yellow colour, and often interfei-^cd with veins of copper or 
tin : fiirface undulated : frafture long, fplintery, imporfeflly 
flaty : lulfre opakc, filky: co.itains filica 0,60. argil 0,25. 
niagnefu 0,09 iron 0,06. and fome petrol or bitumen. 
Kirnxsan. 
^'igrica. Peep black, meagre, very folt, foiling the fingers, making . 
a black {freak, of .tn incurved flaty texture, breaking 
into difeoid fragments or long fpl inters, becoming 
redditli-grey in the hrc. 
Schiftus feriptura atra. Sv/l. nat. xii. 3. p. 38. n. 9. 
Schiftus mollis niger. Wall. fist. \ .p. 343. «.8. 
Black chalk. Kh’ixsan mineral. 1./ IQS- 
Black chalk. Schmsiffer miner. 1 . p. 173, Thorn/. 3. /, 533 . 
Found in iTcstrcgath^ Franconia^ and Italy^ in folid malles, 
without luftre: adheres flightly to the tongue, feels ftnooth, 
afi'umcs a polifh from a knife, gives a bhek ftreak and marks 
black, does not readily moulder in water, or effervefee or dif- 
folvein acids, when heated torednefs becomes reddifh-grey : 
contains fllica 64,60. alumina 11,2^. charcoal 11, oo. oxyde 
of iron 2.75. water 7,50. If'eigleb. 
ftssularis. Very foft, fomewhat ponderous, breaking into trapezoid 
fragments, of a flaty texture. 
Schiftus rhombeus. Gerh. Bcytr. min. 1 . p. 343, n. 5. 
Found in Silelia near GolSerg and Neudorf, forming entif^ 
fountains, of a brown, pale yellow, or green colour. 
