188 PHYSIOGRAPHY. 



ture more and less imperfectly and thick slaty, 

 sometimes fine earthy. Cross fracture fine earthy. 



Faintly glimmering, dull. Colour ochre-yellow. 

 Acquires some lustre in the streak. Opake. 



Sectile. Adheres rather strongly to the tongue. 

 Soils a little and writes. Is very soft, partly also 

 friable. Sp. Gr. = 2-240, BBEITHAUPT. 



If thrown into water it falls into powder and emits a 

 noise. If burnt it becomes red. It is a mixture of fine 

 sand, oxide of iron, clay, &c., and occurs at Wehrau in Up- 

 per Lusatia, in France, &c. It is employed both in its na- 

 tural state and burnt, in painting houses, &c., as a coarse 

 colouring, material. 



