TRIPOLI. 185 



all to the tongue, is very soft, passing into friable. 

 Sp. Gr. = 0-590 ... 0-606, HABEKLE. 



It imbibes water, but does not fall to pieces. It be- 

 comes red when burnt, but is infusible. It consists, ac- 

 cording to BUCHOLZ, of 



Silica 79-00. 



Alumina 1-00. 



Lime 1-00. 



Oxide of Iron 4-00. 



Water 14-00. 



It is believed to have been formed from the ashes of 

 burnt coal. It occurs at Planitz near Zwickau, and at 

 Kutschlin near Bilin in Bohemia. 



TETPOLI. 



Tripoli. JAM. Syst. Vol. II. p. 71. Man. p. 470. Tripoli. 

 PHILL. p. 53. 



Massive. Composition impalpable. Fracture earthy 

 in the small, sometimes slaty in the great. 



Colour grey, more particularly yellowish- and ash- 

 grey, passing into white and yellow. Opake. 



Not particularly brittle. Does not adhere to the 

 tongue, feels meagre and a little rough, is said to 

 be soft passing into very soft (it is nevertheless 

 applied as a powerful material for polishing). 

 Sp. Gr. = 1-857, DELAME'THERIE ; =2-202, 

 BUCHOLZ. 



It imbibes water, which softens it. When burnt it be- 

 comes white, and is hardened ; but it is very difficultly fu- 

 sible. It consists, according to BUCHOLZ and HAASE, of 

 Silica 81-00 90-00. 



Alumina 1-50 7-00. 



