216 31 in era logica I No tices. 



view that they are pseudomorphs of olivine. There are three 

 crystals which have an interior of ohvine, A portion of a crystal 

 from Snariimj received from Quenstedt^ afforded Hefter ia his 

 laboratory, 



Si Slg f^e "Mn fi 



41-93 5318 2-02 0'25 4-00 = 101-38 - ; G = 3-0384 



Oxygen 21'79 20*58 0*46 006 3-58 



Showing that it is a mixture of olivine and serpentine. The 

 crystals of Snariim and of the Fassa valley in the Tyrol are there- 

 fore pseudomorphs. The villarsite of Dufrenoy, which is similar 

 in its crystalline forms, he refers to the same origin. He regards 

 serpentine as an amorphous material incapable of crystaUization. 

 Substances perhaps occur imperfectly crystallized; having the 

 same composition; but the only substance of this nature, which 

 he recognizesj is chrysotile. Schiller spar, which is allied in com- 

 position, the author regards as no natural mineral in crystalliza- 

 tion, but a pseudomorph after augite, with which it is often asso- 

 ciated. He alludes to the frequent occurrence of serpentine 

 pseudomorphs imitative of many of the mineral species, as horn- 



blende, augite, garnet, chondrodite, spinel, mica, &c. 



Serpentine of the Vosges. — The serpentine of the Vosges and 

 its associated minerals, have been investigated chemically and 

 otherwise by M. Delesse (Ann. d. Mines, [4], xviii, 309), whose 

 descriptions are very full and complete. The minerals noticed 

 are garnet, chromic and magnetic iron, iron pyrites, diallage, 

 chlorite, chrysotile, calcite, dolomite, nemalite, brucite, feldspar, 

 quartz, talc, asbestus, and specular iron. 



Garnet occurs of red, brownish and greenish or grayish-green 

 colors- B.B. it fuses with difficulty, and in a tube yields some 

 water. H. =^6'5. G. =3'150, Composition : 



Si 3tl Sr f'e Sta Mg Ca 



41*56 19-84 0-35 10'17 trace 22 4*25, ign. l-58=99*75 



Diallage is sometimes disseminated through the serpentine, but 

 occurs commonly in small masses or in the intersecting veins. 

 Color deep olive-green, and occasionally, emerald green. The latter 

 variety is sometimes found within a nodule of garnet. Lustre a 

 little pearly but not like bronze. G— 3-154. Analysis gave 



Si Sr, Stn Fe ]$ig (by diff.) Ca 



56-33 1-50 6-73 31-93 1-40, ign. 2*11 =100 



The 211 p. c. given off by heating are nearly all water. Form- 

 ula S= Si. 



Chlorite occurs in veins or in nodules of garnet, and evidently 

 the garnet has been altered to chlorite, as the different stages of 

 the process may be detected. B.B. becomes grayish and takes a 

 metallic lustre, and if in lamellae the edges are rounded, forming 



\ 



