268 Professor Gmelin's Analysis ofHelvine. 



Art. XVI. — Analysis ofHelvine. By C. G. Gmelin, Pro- 

 fessor of Chemistry in the University of Tubingen. Com- 

 municated by the Author. 



This very rare mineral occurred formerly in a peculiar bed- 

 formation, (Lager-f.) on primitive mountains, accompanied by 

 brown blende, fluor spar, quartz, schiefer spar, chlorite, &c. 

 in the neighbourhood of Schwarzenberg, in the Saxon Erz- 

 gebirge. The first notice and previous characteristic of it was 

 communicated by Professor Mohs,* who placed it in an ap- 

 pendix close to common garnet, as a mineral not yet deter- 

 mined. Werner made a peculiar species of it, which he placed 

 in his system between colophonite and garnet, and named it, 

 on account of its marked yellow colour, Helvin, after the 

 Greek ^«>s, the sun. Professor Mohs, in his Grundriss der 

 Mineralogie, joined the Helvine to the genus garnet, by the 

 name of tetrahedral Garnet. Mr Breithaupt placed it in his 

 sphen-kiesel genus, and Mr Cordier thought that it might be 

 united with Crichtonite, a sparry magnetic iron-ore, contain- 

 ing: oxide of titanium. 



We possess alreadv a chemical analysis of Helvine by Dr 

 Vogel of Munich, -f- according to which it is composed of — 



Silica - 39.80 



Alumine - - 18.65 



Lime - - 0.50 



Oxide of iron ... 37.75 



Oxide of manganese - 3-75 



97.15 



The action of the blow-pipe upon Helvine clearly shows, 

 as has already been observed by Professor Berzelius, j that 

 manganese is a principal ingredient in this mineral, and that iron 

 can only be contained in it in a small quantity. The method 

 of separating iron from manganese, followed by Dr Vogel, 



* Beschreib- des von der Null schen Minerallien Kabinets, Abth. p. 92. 

 t Schweigger's Journal, Vol. XXIX. p. 319. 

 X Use of the blow-pipe, &c. 



