170 



VESUVIAN ROCKS 



u 



Upper Meionite, Vesuvian Scapolite (silicate of lime and alumina ». 



Galleey. r v J J 



• • 



• • 



Table-case 

 a Recess 4. 



Ca 3 Si + 2 Al Si. 



100 to 111. — Various specimens of meionite in lime- 

 stone from Monte Somma. The clouded and rounded 

 masses form the variety " Nutallite " of Brooke, which 

 is distinguished by its inferior hardness. 



Idocrase Vesuvian {silicate of alumina of lime). 



112. — Brown idocrase, with augite and mica. 

 113. — Idocrase, with felspar, augite, and mica. 

 114. — Reddish-yellow idocrase, with felspar. 

 115. — Yellow idocrase, with felspar, mica y 



and 



augite. 



116. — Idocrase, with augite and nepheline in limestone. 

 117. — Idocrase in rounded crystals, with mica and mei* 



onite. 



118. — Meionite and idocrase on limestone. 

 Somma. 



Monte 



Olivine (silicate of magnesia lime Fe 2 3 and M 0). 



119 



120 

 121 



Olivine, filling the hollows of a vesicular lava. 

 Green olivine, with granular green augite. 

 Vesicular lava, with acicular hornblende crys- 



tals. 



Mica {silicate of alumina Fe 2 3 and potash.) 



122. — Crystals of greenish-black mica much eroded. 

 123. — Small mica crystals, with augite in limestone. 

 124. — Mica crystals, with chondrodite {silicate of mag- 



nesia) in limestone. 



125. — Lava, with augite crystals and a little chondro 



dite. — Capo di Guoglio. 



. 126. — Similar specimen from the same locality. 



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