Helvine Enlarge
[Undated]
Exotic Mineralogy
CLXIV
Helvine

  • Syn. Helvin, Friesleben’s Beiträge zur Min: Kenntniss von Sachsen, b. 1. s. 126. Cordier, Ann: des Mines for 1818. Heuland in Annals of Phil: XII. 453.

It does not appear that this mineral has yet been analyzed, we are therefore uncertain what genus to place it under. It has been found only in the mine called Brother’s Lorenz, near Schwarzenberg in Saxony, Avhere it is imbedded in dark green almost compact Chlorite, accompanied by lilac Fluor, Blende, Schaalstein and Quartz, its crystals are sometimes connected together, but are rarely attached to the gangue; the most common form is an octohedron, four of whose faces are much smaller, of a deeper colour and more transparent than the others, sometimes these faces are very minute and even quite wanting, when the crystals become regular tetrahedrons with brownish yellow angles. Its lustre is about equal to that of Garnet, the fracture is uneven and rather splintery, by close attention indications of laminæ parallel to the sides of the crystals are observable. The hardness varies in the same crystal, the opaque parts yeilding to the knife while the transparent scratch crown glass. The specific gravity is from 3.2. to 3.3.; before the blow-pipe it fuses easily into a blackish brown glass. The yellow colour resembling that of the Sun when low in the horizon has given rise to its name.

I am indebted to Mr. Heuland for the use of the fine specimens figured.

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