Page:Transactions NZ Institute Volume 15.djvu/499

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occurs as veins traversing serpentine and hornblende schist, one variety being speckled with chromic iron. It is found as boulders, sometimes of great size, in the auriferous wash of a few localities on the West Coast, such as the Kumara diggings, on the banks of the Teremakau River, and the Greenstone diggings near Lake Brunner. Two analyses of this mineral, quoted by Dr. Hector (Jurors' Rep. N.Z. Ex., 1865, p. 413) give the following composition:—

Silica	51.08		56.00
Protoxide of iron, with traces of manganese and chromium	12.43	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	11.13
Alumina	1.42		11.13
Lime	9.00		9.94
Magnesia	21.35		21.96
Soda	traces		traces
Water of constitution	.97		.97
	96.25		100.00

Diallage, (Ċa, Ṁg, Ḟe) S̈i.—The first mention of this mineral in New Zealand is by Dr. Hector (Jurors' Rep. N.Z. Ex., 1865, pp. 266, 438) as occurring in diorites on the West Coast, and during his trip round the West Coast Sounds in 1863, he collected specimens in gabbro from Hokuri Creek, Martin's Bay, Lake McKerrow, and the head of Kakapo Lake; he again mentions it (Trans. N.Z. Inst., vol. ii., p. 377) as dykes in the Dun Mountain. It is mentioned by Dr. v. Haast as occurring in gabbro in the Mt. Torlesse Range and Upper Rakaia (Jurors' Rep. N.Z. Ex., 1865, p. 257); by Mr. J. C. Crawford in reefs traversing mesozoic limestones at Waikekino (Trans. N.Z. Inst., vol. ii., p. 351); by Mr. E. H. Davis, at the Dun Mountain (Geol. Rep., 1870–71, p. 112); and again by Prof. Liversidge in his description of the minerals in the Otago Museum (Trans. N.Z. Inst., vol. x., p. 496), from Lake McKerrow and Dun Mountain. There is a specimen in the collection of the Colonial Museum, from Kakapo Lake, of a dark-green colour and metallic lustre, which is not well marked, corresponding with the specimen described by Prof. Liversidge from Lake McKerrow.

Hypersthene, (Ṁg, Ḟe) S̈i.—This mineral is mentioned by Dr. Hector in diorite rocks on the West Coast (Jurors' Rep. N.Z. Ex., 1865, pp. 266, 438), and was collected by him from Warp Point, Kaduku River, in 1863. It is again mentioned by Dr. v. Haast in hypersthenite, Malvern Hills (Jurors' Rep. N.Z. Ex., 1865, p. 257); by Mr. E. H. Davis at the Dun Mountain (Geol. Rep., 1870–71, p. 112); and by Prof. Liversidge as occurring in the collection of the Otago Museum from Warp Point, Kaduku River (Trans. N.Z. Inst., vol. x., p. 497).