1905-1906. 



THE CARNMONEY CHALCEDONY 

 Its Occurrence and Origin. 



(With a General Note on the Formation of "Secondary' 

 Siliceous Minerals in Volcanic Lavas). 



By JAMES STRACHAN. 



Being an Appendix (No. 8 of Vol. II.) to the Proceedings of the 

 Belfast Naturalists' Field Club, for 1905-6. 



