Triphane, Spodumene Enlarge
Oct. 1. 1811 published by Jas Sowerby London.
Exotic Mineralogy
XXII
Silex spodumenum

Triphane, Spodumene

  • Syn.
    • Triphane. Haüy, Tabl. 37. Traité, 4. 407.
    • Spodumen. Werner.
    • Spodumène. Dandrada, Journ. de Phys. Fructidor, an 8, p. 240.

This mineral, described by Dandrada, was found at Uton in Sweden, and also in Norway, disposed in Granite (Quartz with a little Feldspar and Mica), in various directions, in oblique four-sided more or less battery prisms, composed of plates, and which are generally narrowest on the most readily divisible sides. The surface of the plates is of a light green colour, but the prism terminating irregularly in the matrix, no apex, or even external surface, is to be discovered, and the cross-fracture shows dull small roughish fragments, and appear of a darker green colour. See the middle of the specimen. The middle geometrical figure shows the twofold direction of the lamina, and the diagonal fracture included in a square, and the manner in which the narrow sides are lost in the matrix, which in this specimen is mostly Quartz with a tinge approaching to purplish. The right-hand geometrical figure shows what Haüy considers as nearly the form of the nucleus, the angles of which are about 80°. and 100°. with the irregular oblique fractures on the sides. The other uncoloured one shows the nucleus distinctly, with the approximation at the diagonals of the two right-angled planes, to form the oblong parallelogram.

It is so hard as to scintillate with steel, scratch glass, &c. Heated in a crucible, it splits into numerous plates, some yellow, some dark grey; all lose their lustre in a few days, and are of the latter appearance. Before the blow-pipe it melts into a greyish globule. Spec. Grav. 3.1923 to 3.218.

Analysis by Vauquelin. More recent by the same.
Silica 56.5 64.4
Alumina 24.0 24.4
Lime 5.0 3.0
Oxide of iron 5.0 2.2
Loss 9.5 Potash 5.0
Loss 1.0
100.0 100.0
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