Pyrargyrite

St Andreasberg Mining District, Lower Saxony, Germany

A single pyrargyrite crystal, exactly 1 cm long, from the historic silver mines of Sankt Andreasberg in the Harz Mountains. Its form is unusual: prismatic sections grow side by side in parallel and split at the top into two terminations, and a small crystal juts out sideways near the base. The faces are sharp and finely striated, steel gray to black with a bright submetallic luster and a faint iridescent tarnish. The crystal is mounted with wax on a cork inside a glass vial, in the traditional way of keeping such small pieces. Pyrargyrite darkens under strong light; kept in its vial and away from direct sun, it will stay as it is. Pyrargyrite, the “dark ruby silver” of the old miners, was among the most sought-after minerals of Sankt Andreasberg. Mining there began in the early sixteenth century and ended in 1910 with the closure of the Samson mine, today part of a UNESCO World Heritage Site. A small, finely formed crystal from a find that will not be repeated.