Cox. — On the Mineralogy of Neiv Zealand. 



385 



Dolomite, Ca C + Mg C. — Dr. v. Haast mentions the occurrence of this 

 mineral at the Malvern Hills (Jurors' Eep. N.Z. Ex., 1865, p. 256) inter- 

 stratified with augitic greenstone, and it was collected by Dr. Hector in 

 1872 from Collingwood. 



Pearlspar. — A specimen of this mineral was collected by Dr. Hector in 

 1878, from the Big Pump Shaft at the Thames. 



Epsom-salt, Mg S + 7 H. — Dr. Hector mentions the occurrence of this 

 mineral on Murison's station in Otago (Jurors' Eep. N.Z. Ex., 1865, p. 438). 



Salts of Alumina. 



Taranakite. — This mineral, which is a double hydrous phosphate of 

 alumina and potash, part of the alumina being replaced by ferric oxide, was 

 first discovered by H. Eichmond, Esq., at the Sugar Loaves, Taranaki, 

 where it occurs as thin seams which occupy fissures in the trachytic rocks. 

 It is described by Dr. Hector (Juror's Eep. N.Z. Ex., 1865, p. 423) as of 

 a yellowish- white colour ; amorphous and soft ; readily fusible before the 

 blowpipe, and in other respects resembling wavellite. It has the following 

 composition : — 



Phosphoric acid 





35-05 



Alumina 





21-43 



Ferrous oxide 





4-45 



Lirne 



. , 



•55 



Potash 





4-20 



Soda 





traces 



Chlorine 





•46 



Sulphuric acid 





traces 



Insoluble in acid (silica) 





•80 



Water driven off at 212° . 



15-46) 



33-06 



„ ,, ,, red heat 



17-60/ 





100-00 

 and has a slight acid reaction. 



Wavellite, j$ P 2 + 12 H. — Occurs as thin seams of a dark, yellowish- 

 brown colour, hard, translucent, and infusible, traversing the taranakite in 

 various directions, and is mentioned by Dr. Hector (Jurors' Eep. N.Z. Ex. 

 1865, p. 424). 



Alitnogene, J£ S 3 + 18 H, is mentioned by Dr. Hector (Jurors' Eep. 

 N.Z. Ex., 1865, p. 438) as occurring in some of the brown coals. In 1867 

 a specimen was forwarded from Tuapeka by Dr. Halley, which proved to be 

 nearly pure sulphate of alumina. It was colourless and well crystallized 

 and completely soluble in water. The following analysis shows that its 

 composition is — 



Sulphate of alumina, with traces of sulphate of lime. . 



Sulphate of lime . . 

 ,, magnesia 



Alkaline sulphates 



Water 



25 



100-00 



