364 



PROCEEDINGS OF THE XATIONAL MJ^SEUM. 



prism Mi is deeply striated and the other forms are all narrow. 



(No. 82868, U.S.N.M.) 



SCHNECKENSTEIN. 



This locality is represented by a good single 

 crystal, about 1 cm. broad, and a few doubly ter- 

 minated ones in the matrix. They have a pale 

 yellow color. 



Four dift'erent types of the Schneckensteiu crys- 

 tals have been described by Griinhut,^ distin- 

 guished by the presence and size of certain forms, 

 especially of the brachydome/ |021|. The best 

 crystal in the collection belongs to his first tyi)e, 

 but is lacking in some of the rarer forms which 

 lie mentions. The type is quite similar to the 

 Ilmen Mountain crystals. 



Fig. 9 shows tlie most general combination, 

 ismatic zone is enriched by the presence of the two narrow 

 g 1130 1 and M |230| and the pinacoid h j01()(. The three 



•Topaz irystai 

 Nerchinsk. 



The pr 

 prisms 



I'lG. 8.— Topaz crystai- from Nerchinsk. 



Fu;. 9. --Topaz CRYSTAL FROM Schneckenstein. 



brachydomes y, /, and X are present, ./" i)redominating, and X very 

 narrow. The prism faces are striated. (No. S2'>30, TT.S.ISr.M.) 



AUSTRALIA. 



There is but one representative of this 

 country in the collection. It is a colorless, 

 about 1 cm. broad, crystal with somewhat 

 rounded faces. In tyi^B and combination 

 it is exactly similar to the Adun Chalon 

 crystals. 



•TAPAN. 



Fig. 10.— Topaz CRYSTAL FROM Japan. 



The collection contains a few colorless 

 and more or less waterworn crystals from Takayama Mura. They are 



iZeit. Kryst., 1884, IX, p. 124. 



