Page:Transactions NZ Institute Volume 15.djvu/503

Heulandite, …Al S̈i³ + Ċa S̈i³} + 5 Ḣ.—The occurrence of this mineral in amygdaloidal traps associated with felsite porphyries in Canterbury, is mentioned by Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p. 257).

Apophyllite, 8 (Ċa S̈i² + 2 Ḣ) + K F, is mentioned by Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p. 267) occurring in amygdaloids at Rangitata, and ichthyophthalmite in felsite porphyries at Turnagain Point, Rangitata.

Stilbite, …Al S̈i³ + Ċa S̈i³ + 6 Ḣ, is mentioned as occurring at Turnagain Point, Rangitata, by Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p. 257). It also occurs at Tokatoka on the Wairoa River, Auckland, as radiating pearly crystals in a trachytic rock which forms Mts. Maungarahu and Tokatoka, and it is again found in a similar rock which occurs at Pukekorero, a mountain lying between the Kaiwaka arm of Kaipara Harbour and Mangawhai. Prof. Liversidge (Trans. N.Z. Inst., vol. x., p. 500) also alludes to its occurrence at Dunedin in amygdaloidal basalts as follows:—"In the cavities of these specimens are minute detached crystals of one of the zeolites. The form appears to be that of a rhombic prism capped with the pyramid; this is a combination often assumed by stilbite, and in addition the little crystals possess a very high lustre, not unlike that of stilbite; moreover, they behave like that mineral before the blowpipe, hence they probably belong to the same species.

Prehnite, …Al S̈i + 2 Ċa S̈i + Ḣ.—This mineral is mentioned by Dr. Hector (Jurors' Rep. N.Z. Ex., 1865, pp. 266 and 437) as occurring in the trap rocks of Moeraki and Otepopo, and R. Daintree, Esq., F.G.S. (Trans. N.Z. Inst., vol. vii., p. 458), in speaking of a granite rock from the Snowy Peak Range, Canterbury, says:—"There is a yellowish mineral with a fibrous radial structure seen both in the specimen and the section. It is evidently a secondary formation, filling spaces between the constituents. It is probably prehnite.

Natrolite, …Al S̈i² + Ṅa S̈i + 2 Ḣ.—The occurrence of this mineral in vesicular basalts near Dunedin is mentioned by Dr. Hector (Jurors' Rep. N.Z. Ex., 1865, pp. 267 and 438), and in the volcanic rocks of Banks Peninsula, by Dr. v. Haast (Jurors' Rep. N.Z. Ex., 1865, p. 257). It is also mentioned in the old catalogues of the Otago Museum as specimens from Oamaru in trachyte, from Mount Livingstone and from Look-out Point. There are numerous specimens of this mineral in the collection of the Colonial Museum, in cavities in the basalts from Dunedin. They are arranged in beautiful little tufts of fine acicular crystals, sometimes alone, and sometimes on chabasite; in other specimens they are massive but mammillated, and in others they are composed of short rhombic prisms with pyramidal ends, but these also occur in tuft-like groups. There is also a