236 Intelligence and Miscellaneous Articles. 



Atheriastite. — This mineral was long confounded with paranthine ; 

 it is found in an abandoned iron mine at Naes, near Arendal, ac- 

 companied with black garnet and keilhauite in a granitic rock. 



Its primary form is an octohedron with a square base, the adjacent 

 faces of which form angles of about 135°; this octohedron is accom- 

 panied by two square prisms. The crystals are short and thick, 

 and the angles and edges are usually rounded. Cleaves readily 

 according to the second square prism. Fracture uneven and splin- 

 tery, dull or chatoyant. Colour pale green, powder greenish gray ; 

 opake. 



It swells before the blowpipe, and readily fuses into a deep brown 

 glass. Hydrochloric acid attacks it very feebly. 



By M. Berlin's analysis it yielded — 



Silica 38-00 



Alumina 24*10 



Lime 22*64 



Magnesia 2*80 



Protoxide of iron 4*82 



Protoxide of manganese . . 0*78 



Water 6*95 



100-09 



If a part of the iron be supposed to be in the state of peroxide, 

 this composition may be represented by the formula — 



2(3CaO, SiO 3 ) + 3A1 2 O 3 SiO 3 +4Aq. 



Eudnophite. — This mineral was found in the syenite of the island 

 of Lamoe, with the two first minerals above described. Its crystals 

 are very rare ; they are derived from a right rhombic prism, giving 

 a prism of about 130°, terminated by a bevil, and truncated at the 

 acute edges. Cleavage perfect according to the base ; there also 

 exists a more difficult one according to the diagonal planes. Frac- 

 ture even, slightly splintery. The faces are dull or a little brilliant, 

 lustre slightly pearly when fractured. Colour white, passing to 

 gray or brown ; powder white. Fragments translucent or trans- 

 parent. Hardness between that of felspar and apatite. Density 2*27. 



Before the blowpipe this mineral fuses into a colourless glass. 

 Reduced to powder, it is decomposed by hydrochloric acid with the 

 formation of gelatinous silica. 



It has been analysed by M. de Bock (I.), and by M. Berlin (II.). 



(I.) (HO 



Silica 54-93 55-06 



Alumina 23-59 23*12 



Soda 14-06 14-06 



Wate"r 8'29 8*16 



100*87 100*40 



These results agree exactly with the formula of analcime, 

 3NaO, 2Si0 3 + 3(Al* O 3 , 2Si0 3 ) + 6HO, and may seem to indicate 



