Page:Transactions NZ Institute Volume 15.djvu/507
fuses easily, and with intumescence to a colourless transparent bead. Easily decomposed by hydrochloric acid, with separation of gelatinous silica.
Analysis.
| Silica | 44.71 |
| Iron | 14.66 |
| Alumina | 11.47 |
| Lime | 22.93 |
| Magnesia | 2.13 |
| Water of constitution | 4.10 |
| 100.00 |
Kyanite (Disthene), S̈i.—This mineral is mentioned in the Catalogue of the Colonial Museum (p. 119) from Westland. The specimen is of a beautiful cobalt blue colour, and associated with quartz. The crystals are not very distinct.
Chiastolite.—Crystals of this mineral, of a dirty-grey colour, imbedded in clay slate, from Slate River, Collingwood, are in the collection of the Colonial Museum.
Leucite, 2 S̈i3 + K̇ S̈i.—The occurrence of this mineral in leucitic basalt is mentioned (Col. Mus. and Lab. Rep., x., p. 48) from Castle Point, Napier, having been collected by Mr. A. McKay.
Scapolite, 2 Si3 + (Ċa, Ṅa) S̈i.—The occurrence of this mineral in a massive form at the Dun Mountain is mentioned by Mr. E. H. Davis (Geol. Rep., 1870–71, p. 112), and an impure form of the same mineral was forwarded from the Maitai Valley, by the Nelson Museum, in 1868. The specimens collected by Mr. E. H. Davis were analyzed at the Colonial Laboratory, with the following results;—
| (1.) | (2.) | (3.) | |||
| Silica | 48.63 | 48.29 | 43.06 | ||
| Lime | 25.39 | 26.59 | 24.34 | ||
| Alumina | 20.70 | 20.47 | 11.47 | ||
| Iron sesquioxides, with manganese | traces | traces | 7.24 | ||
| Magnesia | 2.93 | .85 | 9.06 | ||
| Water | 2.35 | 2.53 | 3.42 | ||
| Loss | . . | 1.27 | 1.41 | ||
| 100.00 | 100.00 | 100.00 |
Nos. 1 and 2 are white minerals, with rare mottlings and striæ of a dark red colour; they are dull and opaque, but in thin sections translucent; easily fusible in the blowpipe, with intumescence to transparent beads, giving faint reaction of soda. No. 3 has a general similarity to the others, but is uncoloured, and fuses to a yellow-coloured bead in the blowpipe