Page:Transactions NZ Institute Volume 15.djvu/487
Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p, 256) states that it occurs lining fissures and cavities in the volcanic rocks of Banks Peninsula. In 1869, Capt. Hutton collected specimens from the Eldorado claim, Thames; in 1870 a specimen with calcite was forwarded from Oamaru by Mr. Traill; in 1875 Mr. McKay collected specimens from Whangaroa North, and in 1877 another from Waitaki. Prof. Liversidge (Trans. N.Z. Inst., vol. x., p. 493) describes four specimens from Dunedin, three of these being in amygdaloidal cavities, associated with calcite, and corresponding with the specimen I collected from Seacliff (mentioned under calcite, p. 381); the fourth being rosettes of pale yellow-coloured prisms. The acicular crystals of carbonate of lime mentioned by Dr. Hector (Handbook of N.Z., Melbourne Exhibition, 1880, p. 108) as deposited from a hot spring at Waipiro are also probably aragonite. The specimens in the Colonial Museum are:—
1. Crystals of Aragonite.—Eldorado Claim, Thames. A pure white transparent variety in prismatic crystals, consisting of the prism ∞P, the brachypinacoid ∞P̆∞, and the brachydome P̆∞.
2. Crystals of Aragonite.—Quartz hills, Collingwood. These include a large collection which I made during the summer of 1880, some of the groups of crystals being of exceeding beauty. They occur under somewhat unusual circumstances, having crystallized in small recesses about a foot deep in an isolated patch of limestone which occurs there. They consist chiefly of rhombic prisms, macled along a face of ∞P. They sometimes assume a more or less radiate form, but far more frequently interlace, forming a most beautiful network of fine acicular crystals. In some cases again they occur as little tufts of cream-coloured crystals about half an inch in diameter, and again as small bunches of acicular crystals, which are frequently terminated by very small stalactites. They are generally of a pale cream colour, but in some cases are brown, owing to the presence of ferric oxide.
Gypsum (Selenite), Ċa + 2 Ḣ.—This mineral occurs in several localities in New Zealand, either in groups of crystals associated with sulphur, as on White Island, where it also occurs in a massive form with sulphur disseminated through it; or as nests of crystals in clay or marl, as at Moeraki and Waihao. The first mention of it in New Zealand is by Dr. Hector (Jurors' Rep. N.Z. Ex., 1865, pp. 35, 266, 422, and 437), who states that it is found crystallized in clay at Moeraki, and also in lenticular masses at the same locality. It is again mentioned by Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p. 256) occurring as crystals on the surface of tertiary shales at Tenawai. Dr. Hector also mentions the occurrence of gypsum (Trans. N.Z. Inst., vol. ii., p. 367) in the auriferous rocks of the Thames (Trans. N.Z. Inst., vol. iii., p. 278), at White Island (Geol. Rep., 1873–74, pp. xii. and xviii.) in the sulphur sands of Amuri Bluff and the