Höllgraben, Pfarrwerfen, Werfen, Salzburg, Austria

A small southwestern branch of the Salzach valley, located just west of Pfarrwerfen. Along the valley, the stream cuts through numerous mineralized veins disseminating greenschists of the Werfen series (so-called Werfen schists). There are four types of veins, exhibiting different mineralizations:

QUARTZ VEINS: Mainly massive quartz, with some crystallized chalcopyrite, breunnerite, barite and lazulite
QUARTZ-BREUNNERITE VEINS: Eutectic mixture of quartz and breunnerite, rarely accompanied by small, poorly formed lazulite crystals. Only the wider veins contain vugs with well crystallized minerals. Wagnerite is rare in this association.
BREUNNERITE VEINS: Mainly massive breunnerite. Vugs in the middle of the veins contain well crystallized specimens. Lazulite is rare, but wagnerite occurs abundantly, the crystals reaching up to 20 cm in length.
BREUNNERITE-GYPSUM VEINS: These veins mainly consist of finely grained, massive gypsum, associated with crystallized anhydrite and aragonite. Breunnerite is present near the contact to the schists. Phosphates do not occur in this association.

In the upper valley, the schists are contacting limestones and dolomites of the Gutenstein formation. In vugs near this contact, large, well formed crystals of gypsum, chalcopyrite and mesitine spar occur. Mineralized clefts in the carbonatites themselves contain fluorite, crystallized carbonates and, rarely, rutile.

References:
- A. Strasser: Die Minerale Salzburgs, 1989