The current work and search for minerals is performed in the lower dolomite levels of the Lengenbach quarry, directly in front of the concrete hall.
Ralph Cannon, technical head of the FGL, checks the mineralization in the realgar-rich dolomite area of zone 1.
Consequent manual labor sometimes leads to interesting mineral samples...
... as seen here in form of a prismatic, lead-grey, metallic lead-arsenic-sulfosalt (baumhauerite), up to 2 cm, in a typical small calcite cavity.
Also small realgar veins crossing typical fracture surfaces (so called "picasso" surfaces, pale red in the foto) can host well crystallized minerals, like tennantite ("binnite"), hatchite-wallisite, imhofite, edenharterite, jentschite, and others.
(Thomas Raber and Ralph Cannon photos)