86 PHYSIOGRAPHY. 



Fragile. Hardness between 3-0 and 4-0. Sp. Gr. = 

 000, of a conchoidal variety; from 1-727 ... 

 1-870, the earthy varieties. 



It consists, according to BRANDES, of 



Conchoidal var. Earthy var. 

 Silica 46-00 45-00. 



Oxide of Iron 35-30 32-00. 



Manganese 2-00 0-00. 



Alumina 1-00 0-75. 



Water 18-00 20-00. 



Manganese a trace 2-00. 



Potash a trace a trace. 



It is remarkable for a very singular magnetic property. 

 When taken from its original repositories, it breaks pretty 

 readily in a kind of parallelepipeds, the upper end and two 

 adjoining lateral edges having the opposite magnetic poles 

 from the other two edges and the lower end. It is not 

 phosphorescent. 



It has been found accompanying uncleavable Quartz 

 near Unghwar, in the county of the same name in Hun- 

 gary, and is often called Green Iron-Earth. 



CHLOROPHAEITE. 



Chlorophaeite. MACCULLOCH. Western Isles. Vol. I. p. 

 504. PHILL. p. 202. 



Massive: in small grains, imbedded in basalt or 

 amygdaloid, and sometimes hollow. Fracture 

 conchoidal ... nearly earthy. 



Colour pistachio-green and transparent, or opake ; 

 but soon turning into brown and black on being 

 exposed to the air, without losing its lustre, 

 which takes place also to the depth of an inch or 

 two into the rock. 



