Cox.—On the Mineralogy of New Zealand. 887 
Non-Meratiic Minerats.—Class V. 
Earths (Silica and Alumina). 
SILICA. 
Quartz, Bi.—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 Rakaia Gorge, 
Canterbury, are in the collection of the Colonial Museum, and Dr. v. Haast 
mentions its occurrence in amygdaloidal trap (Jurors’ Rep. N.Z, Ex., 1865, 
p. 256) and in the melaphyres of Canterbury (Geol. Rep. 1878-74, 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. 
Praseis mentioned by Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p. 
- 256) as small deposits” in quartzose porphyritic trachytes at the Gawler 
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 
voleanie rócks of Moeraki and Otepopo, and the porphyritie rocks of 
Dunedin Harbour (Jurors Rep. N.Z. Ex., 1865, pp. 266 and 487), 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. 
