Pycnite, Schorlite Enlarge
Mar 1 1812 published by Jas Sowerby London
Exotic Mineralogy
Silex fluatum, aluminiferum

Pycnite, Schorlite

  • Syn.
    • Silice fluaté alumineuse. Haüy, Tabl. 17, note 24.
    • Schorl blanc prismatique. De Lisle, 2. 420. note 137.
    • Schorlatiger Berill. Emmerl. 1. 192. Werner Catal. 1. 231.
    • Schorlite. Kirw. 2. 286.
    • Pycnite. Haüy, 3. 236.

This substance is from Altenberg in Germany, whence the present specimen, by favour of Dr. Nöehden, in my possession, said to be from the bottom of a Tin-mine eighty-five fathoms in depth. It is also found in other places. It is in long partly radiating angular confused bundles of prisms, which are often six-sided, spreading in various directions through the rock, which is an irregularly mixed Granite, with a remarkably large mixture of grey Mica with a lead-like lustre, greyish semitransparent broken Quartz, and a portion of Feldspar ; it is supposed to be primitive. Pycnite has frequent oblique transverse fractures with reddish stains; it is either whitish, yellowish, greyish, bluish, or blush red, and pinky or deeper red; prisms longitudinally streaked; transparency variable; cuts glass; very brittle. It becomes electric by heat.

Haüy, in his Tables, has united this with Topaz, with which it agrees in analysis and many of its characters. How far other Mineralogists may adopt this opinion is uncertain. Werner has joined it with Beryl. Spec. Grav. 3.503 to 3.350.

Analysis by Bucholz.
Silex 34
Alumine 48
Oxide of iron 1
Fluoric Acid 17
Close-up of poster Get a poster »