Cox. — On the Mineralogy of New Zealand. 441 ' 



that the tracliytic rocks, like those of Taranald, and which may be looked 

 upon as mineralogically allied to the granites and syenites on other grounds, 

 also yield an ironsand having a small percentage of titanic iron. 



Where ironsands occur which are intermediate between the two extremes 

 it is due either to a mixture of those derived from two distinct sources, or 

 else the percentage of titanic iron has been increased by the presence of 

 diabase or diorite dykes. 



Meiiaccanite. — Mr. Skey mentions the occurrence of this mineral (titani- 

 ferous iron ore) from Brancepeth, Wairarapa (8th Lab. Eep. p. 15). It 

 occurs with felspar, by which it appears to have been cemented together. 



Iron Ochre occurs as a deposit from chalybeate springs and ferruginous 

 waters in many mines both of coal, gold, and copper. 



Iron Pyrites, Fe". — This mineral is exceedingly widely distributed in New 

 Zealand, indeed may be considered as general in its distribution. At Para- 

 para, CoUingwood, very perfect octahedral crystals are of common occur- 

 rence over part of the limonite deposit previously mentioned, and cubical 

 crystals are of frequent occurrence in the chlorite schists and lepidomelane 

 schists of the metamorphic region of the West Coast and Wakatipu Lake 

 district. 



It is of frequent occurrence as isolated crystals dispersed through the 

 auriferous rocks of the Thames (tufanites), and also in many of the slates, 

 and again forms an important element in the composition of many of the 

 auriferous quartz reefs both north and south. 



It also occurs as important lodes in the CoUingwood district, where 

 several of these are known to occur, and all that have been tested are more 

 or less auriferous in character. These pyrites lodes are found — 



1st. In felspathic slates which are associated with the auriferous reefs, 

 the largest yet known being about 4 feet wide. 



2nd. In the crystalline limestone ; a reef in the Parapara Eiver, above 

 McGrregor's Creek, being at least 8 feet wide, and composed of a fine-grained 

 compact pyrites. As I have previously pointed out it is also probable that the 

 Hmonite deposits of the Parapara are also the back of a large pyritous lode. 



At Mount Eangitoto, in Westland, a pyrites lode, with which is asso- 

 ciated about 20 per cent, galena, occurs, and this is frequently highly 

 auriferous, containing from 5 to 13 ozs. of gold per ton. It is associated 

 with schists and granites. The late Mr. E. H. Davis has described (Trans. 

 N.Z. Inst., vol. iii., p. 287) a new form of kon pyrites, probably a pseudo- 

 morph, from the Chatham Islands. He says : " The system is oblique, 

 nearly isomorphous with felspar, but having the clino- diagonal longer ; the 

 faces, which are smooth and brilliant, are ooP ; OP ; P ; nPoo hemidome, 

 and nPoo clinodome." 



48 



