498 



Transactions, — Geoloijy. 





Analysis. 





Silica . . . . - 



.. 



. . 45-007 



Iron sesquioxide 



.. 



.. 4-138 



Alumina 





.. 37-144 



Potash 



. . 



. . 10-049 



Lime 





■517 



Magnesia 





.. 1-286 



Undetermined constituents, 



water, soda, etc. 



. . 1-859 



100-000 (Liversidge). 

 Presented by Mr. C. H. Hardy. 



Mica. — Dusky Bay. 

 In medium -sized plates ; brown in colour ; associated with quartz and 

 a little decomposed garnet. 



Felspar (Albite)* — George Sound. 

 Fairly well-marked cleavage planes, white, small red stains on weathered 

 surface ; fuses more easily than orthoclase. 



Orthoclase. — Paterson Inlet. 

 Massive, presenting large cleavage planes, of the ordinary pale pink- 

 brown tint. Attached to one end of specimen is some graphic granite or 

 pegmatite. 



Presented by Mr. Kinnear. 



OrtJioclase. — Cooper Bay. 

 Similar to the last. 

 Presented by Mr. Kinnear. 



Orthoclase. — Cooper Bay. 

 Boiled specimens, contain embedded quartz crystals. 



Granite. — Milford Sound. 

 Labelled "lithia mica.f" 



A mixture of white felspar and black mica. No lithia could be detected 

 in this specimen ; both the mica and felspar appeared to be free from it, 

 according to qualitative tests ; therefore, to make doubly sure, the alkalies 

 in both the mica and the felspar were separated and again examined 

 for lithium, but with negative results. 



Alkalies in the Mica. 

 Potash .. .. .. .. .. 3-823 



Soda .. .. .. .. .. 2-136 



5-959 per cent. (Liversidge). 



* Eep. N.Z. Exh., 1865, 487. 

 t Lithia mica occurs in marble at Thomson Sound. Eep. N.Z. Exh., 1865, 437. 



