498 Transactions.—Geoloyy. 
Analysis. 
Silica s af ; ts io .. 45:007 
Tron sesquioxide .. éb 3 P» vs. 4198 
Alumina = = es T s OF Lae 
Potash ʻ 10:049 
Lime : à xe T $3 m 517 
Magnesia  .. ab x S << cc PO 
Undetermined constituents, water, soda, ete. .. ze d 
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. 
Orthoelase.-—Cooper Bay. 
Similar to the last. 
Presented by Mr. Kinnear. 
Orthoclase.—Cooper Bay. 
Rolled specimens, contain embedded quartz crystals. 
Granite,—Milford Sound. 
Labelled “ lithia mica.+”’ s 
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  .. ee - . vo 898 
Soda > nM à x cs 2:136 
5:959 per cent. (Liversidge). 
* Rep. N.Z. Exh., 1865, 437. 
ble at Th Sound. Rep. N.Z, Exh., 1865, 437. 
