Cox. — On the Mineralogy of New Zealand. 387 



Non-Metallic Minerals. — Class V. 



Earths (Silica and Alumina). 



Silica. 



Quartz, Si. — The distribution of this mineral in New Zealand in one 

 form or the other is general. 



Rock Crystal. — The purest form of quartz is represented in the collection 

 of the Colonial Museum by a clear pellucid specimen from Tamata, and 

 some beautiful little crystals from Kereru, Napier, which were forwarded on 

 the supposition that they were diamonds. These small rock crystals occur 

 in many localities in the North Island, being derived from the rhyolitic 

 rocks, which occupy a considerable area in the Taupo district ; and they 

 are again found in Canterbury, where they enter into the composition of 

 the quartz porphyries of Mt. Somers and the Clent Hills ; they have 

 frequently been forwarded for examination from time to time on the sup- 

 position that they were diamonds. Some very beautiful specimens of rock 

 crystal were collected from the Cromwell Company's Mine last year by Mr. 

 McKay, the crystals being sometimes three-quarters of an inch long and a 

 sixteenth of an inch in diameter, the ends being sometimes pyramidal, 

 sometimes hemihedral, and sometimes tetrahedral ; they frequently inter- 

 penetrate one another, and two groups of crystals interpenetrate and pass 

 through very flat and perfectly crystallized rhombohedrons of calcite. 

 Some fine specimens from Milford Sound are also in the collection. 



Amethyst Quartz. — Some very fine specimens from the Eakaia Gorge, 

 Canterbury, are in the collection of the Colonial Museum, and Dr. v. Haast 

 mentions its occurrence in amygdaloidal trap (Jurors' Kep. N.Z. Ex., 1865, 

 p. 256) and in the melaphyres of Canterbury (G-eol. Kep. 1873-74, p. 9). 



Milky Quartz. — Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p. 256) 

 mentions it in the granites of the West Coast, and it is of common occur- 

 rence throughout New Zealand. 



Prase is mentioned by Dr. v. Haast (Jurors' Eep. N.Z. Ex., 1865, p. 

 256) as small deposits in quartzose porphyritic trachytes at the Crawler 

 Downs. 



Jasper. — There is in the collection of the Colonial Museum a specimen 

 from Tinker's Gully, Thames, which is red but gritty, one from Hongikuri, 

 Auckland, also red but gritty, and another from Mahurangi, which is red, 

 with opaline and brown patches. Besides these Dr. Hector has mentioned 

 its occurrence at the Snares (Trans. N.Z. Inst., vol. ii., p. 177), in the 

 volcanic rocks of Moeraki and Otepopo, and the porphyritic rocks of 

 Dunedin Harbour (Jurors' Kep. N.Z. Ex., 1865, pp. 266 and 437), and at 

 Coromandel and Whangaparawa (Jurors' Rep. N.Z. Ex., 1865, p. 253) ; it 

 is mentioned by Dr. v. Haast from the Malvern Hills (Jurors' Rep. N.Z. 



