Park. — On Occurrence of Rare Minerals in N.Z. 365 



Art. XLI. — On the Occurrence of some Bare Minerals in 

 New Zealand. 



By James Park, F.G.S., Lecturer, Thames School of 



Mines. 



[Read before the Atickland Institute, 23rd October, 1893,] 



At the meeting of the Australasian Association for the 

 Advancement of Science, held at Christchurch, in 1891, 1 read 

 a paper describing a number of new and rare minerals found 

 in New Zealand.'" Since that date a number of other 

 minerals have come under my notice, some of them new to 

 this country, and some of them, although previously known 

 here, yet interesting from the exceptional character of their 

 occurrence. 



Cbrvantite (Yellow Oxide of Antimony). 



In the month of January, 1892, Mr. George Wilson, In- 

 spector of Mines for the Hauraki Goldfields, forwarded a 

 collection of ores from the antimony-lode at Waikari, in the 

 Bay of Islands district, to the Thames School of Mines for 

 examination, and the determination of their value. The 

 principal ore in this collection w^as antirnonite, the commonly- 

 occurring grey sesquisulphide of antimony. In several speci- 

 mens the sulphide was incrusted with a layer of the yellow 

 oxide (SbOi) several inches thick. Its hardness was about 5, 

 and specific gravity 4, while its colour varied from yellowish- 

 white to sulphur- yellow. The purest example contained 76 

 per cent, of antimony. 



Cervantite is a most valuable ore of antimony, but is 

 seldom found in large quantities. It generally results from 

 the alteration of the sulphide, and is most frequently found at 

 the outcrop, or shallower parts of antimony-lodes. It is well 

 known at Hillgrove in New South Wales, Oporto in Portugal, 

 and many other foreign localities ; but so far as I can ascertain 

 it has not been previously described from New Zealand. 



Senarmontite (the Grey Oxide of Antimony). 



This mineral was also identified in the collection from 

 Waikari. It frequently accompanies antimonite, but is even 

 less abundant than cervantite. 



In the Colonial Museum and Laboratory report for 1892, 



* " Transactions Australasian Association for Advancement of 

 Science," vol. iii., pp. 150-153. 



