PHY6IOGBAPHY. 



The manganese in Allagite is in the state of peroxide, in 

 all the rest it is protoxide. 



They agree very nearly with the Manganese-spar in re- 

 spect to hardness and specific gravity. Their colours are 

 several green, brown, and reddish tints, which become 

 darker on the surface on being exposed to the air, and 

 generally assume at the same time a slight degree of lustre. 

 They differ in a more or less perfect conchoidal fracture 

 and slight shades of colour, which hardly allow of being 

 expressed in words. They have all been found near Rli- 

 beland in the Hartz. 



MARMOL1TE. 

 Marmolite. NUT TALL. Silliman's Journal, 



Massive. Cleavage in two directions, intersecting 

 each other obliquely, one of them more distinct. 

 Composition columnar. 



Lustre pearly (inclining to metallic). Colour pale, 

 green and grey. Opake. 



Brittle. Easily cut with a knife. Sp. Gr. = 2-47, 



NUTTALL. 



It is said to resemble very much prismatic Talc-mica, 

 with which it had hitherto been confounded. Before the 

 blowpipe it decrepitates, hardens, and splits into laminae, but 

 does not melt. With nitric acid it yields a thick partly 

 gelatinous mass. It consists, according to NUTTALL, of 



Magnesia 46-00. 



Silica 36-00. 



Lime 2-00. 



Water 15-00. 



Oxide of Iron and Chrome 0-50. 

 It occurs in serpentine at Hoboken, and in the Barehills 

 near Baltimore. 



