PLATE XV. 



1. Idocrase, crystalB (Sia9©W»S^,ffl!«PM«<»«ANa- ^W»S%l9P}5fif«»^>™- *■ D'optase 

 oryrtalB (Siberia). 5. Tournall^e. rose-rec^^fnd green crystal i^^iUft)) 6. Tonrmaline, red crystal 

 (Siberia) 7. Tonrmalitfe, green crystal (Brazil). 8, 9. Tourmaline, red and green crystal (Mass- 

 achuaetts) 10. Tourmaline, brown out-stone (Ceylon). 11. Tourmaline, blue cut-stone (Braail). 



