436 Transactions. — Geology. 



1. Loose stones at Mahiirangi, which are composed of siHcate of mag- 

 nesia, and in which Nickel occurs in small and variable amounts. 



2. Portions of a large rock mass of serpentine, which is found cropping 

 out in the direction of Hoteo, from Mahurangi, were found to contain •49 

 per cent. Nickel. 



3. Serpentine from small streams near Manukau North Head, contained 

 •47 per cent. Nickel. 



4. Calcite from Matakohe, stained with hydrated silicate of Nickel. 



5. Hard greenstone from Papakura Valley, gave a trace of Copper and 

 •26 per cent. Nickel. 



6. Green unctuous clay from Waipu, gave •!! per cent. Nickel. 



7. Foliated serpentine from Coromandel, also gave a trace of Nickel. 

 During the past year I visited the locality from which No. 2 of Mr. 



Pond's specimens was obtained and collected specimens of a green siliceous 

 rock which occurs in considerable mass on the Port Albert Eoad from 

 Mahurangi. This rock Mr. Skey reports contains the oxide of nickel at 

 the rate of 1'81 per cent., and appears to be in the form of a silicate. As 

 it occurs as an isolated outcrop, it is impossible to say what its relations are, 

 but seeing that it is free from sulphur and would thus obviate the necessity 

 of roasting before treating in the ordinary way, a small percentage would 

 no doubt pay for extraction, and it appears probable that richer deposits 

 will yet be found in the district. 



Iron. 

 This metal is largely represented in New Zealand, where it occurs 

 in most of the known and more valuable forms both as oxides, sulphides, 

 carbonates, and silicates, besides some interesting samples of phosphate 

 and sulphate and the titaniferous iron ores. 



Magnetite, Pe .]Ze, — This mineral, which consists of a mixture of the 

 ferrous and ferric oxides, does not occur in a massive form in New Zealand, 

 so far as is at present known, but is disseminated through various rocks 

 in minute octahedral crystals and grains. It is principally developed in 

 the chlorite schists on the western side of the main range in the South 

 Island, where in the neighbourhood of Mount Cook, large quantities are 

 found disseminated through the bed rock in the form of minute crystals, 

 which at places become so plentiful as to form beds, interstratified with 

 the schists, from 6 inches to 8 inches in thickness. Similar deposits are 

 found at Lake Harris, in the Wakatipu district, where the Magnetite 

 occurs in small veins and octahedral crystals dispersed through the rock, 

 associated with thin bands of Hematite and crystals of specular iron. It 

 is also largely represented in the volcanic rocks of New Zealand, asso- 

 ciated in many cases with titaniferous iron, and from these rocks the 

 greater quantity of our magnetic iron sand has been derived. 



