This specimen was collected by myself, in Port Adventure, Stewart Island. The mineral occurs there in pieces, weighing from 1 lb. to 15 or 20 lbs. These fragments are derived from the disintegration of the granite. Tons of the mineral could be collected with little trouble. It will obviate the necessity of sending for felspar to other countries for pottery and porcelainware purposes. Acting on my suggestion, Mr. White, of Tokomairirc, has sent for
page 151a quantity of this felspar, and I understand it is found well adapted for these purposes. The mineral yielded to two of the students of the Laboratory, the following results:—
Mr. Will:
Silica |
66.6 per cent. |
Alumina |
18.6 per cent. |
Potash |
12.6 per cent. |
Soda |
2.6 per cent. |
Lime Traces. |
|
Magnesia Traces. |
|
|
100.4 |
Mr. Solomon.
Silica |
58.1 per cent. |
Alumina |
22.0 per cent. |
Potash |
11.9 per cent. |
Soda |
4.3 per cent. |
Lime |
4.7 per cent. |
Magnesia |
0.28 per cent. |
|
101.28 |
The parts analysed were taken from different pieces of mineral.
The large percentage of alkali (15.2 and 16.2 per cont.) makes the stone an excellent flux for glazing in the Pottery Works.