Page:Transactions NZ Institute Volume 15.djvu/504

specimen from Whakahara, on the Wairoa River, Auckland, where it occurs in a vein running through certain tufaceous beds in the Whakahara Saddle, between Maungarahu and Tokatoka. The crystals are long slender rhombic prisms, ∞P with pyramidal ends P.

Chabasite, …Al S̈i³ + Ċa (Ṅa, K̇) S̈i + 6 Ḣ, is mentioned by Dr. Hector in vesicular basalts near Dunedin (Jurors' Rep. N.Z. Ex., 1865, p. 267), and by Dr. v. Haast in the trachyte of Banks Peninsula (Jurors' Rep. N.Z. Ex., 1865, p. 257; there is also in the Catalogue of the Otago Museum a mention of a specimen from Helenburn. The specimens in the collection of the Colonial Museum are all from the first-named locality, and they consist of small rhombohedral crystals in cavities in the basaltic rocks. B.B. it deflagrates slightly and fuses to a porous enamel; colour brownish-white, no soda reaction visible.

Gmelinite, …Al S̈i³ + Ṅa (Ċa, K̇) S̈i + 6 Ḣ, is mentioned by Dr. Hector in vesicular basalts near Dunedin (Jurors' Rep. N.Z. Ex., 1865, p. 267). Specimens from this locality in the collection of the Colonial Museum are pure white, small hexagonal pyramids with OP ends. B.B. gives faint soda reaction only.

Kaolin, …Al S̈i² + 2 Ḣ, is mentioned by Dr. Hector at the Manuherikia Plains and Arrow River (Jurors' Rep. N.Z. Ex., 1865, pp. 267, 438), and at the Whau, Auckland (Jurors' Rep. N.Z. Ex., 1865, p. 35); and I have mentioned its occurrence at Mt. Somers, Canterbury (Geol. Rep., 1876–77, p. 6), where it is formed by the decomposition of felsite porphyries. Specimens from drift at Collingwood have also been forwarded to the Museum.

Clay.—All the varieties of clay are found in the colony, but, for a detailed description of these with their analyses, I must refer the reader to the "Manual of the Mineral Resources of New Zealand," by Dr. Hector, in course of publication. A very fine sample of pipeclay occurs at Hakateramea, Canterbury.

Bole occurs as nests in the doleritic rocks passed through in the Lyttelton tunnel, and is associated with crystals of magnetite. Its specific gravity is 2.089, and composition as follows:—