Argentopyrite, sternbergite, proustite

A rich specimen of rare silver minerals from Jáchymov. The sample features intense red crystals and grains of proustite with clusters of perfectly terminated tiny crystals of the abundant argentopyrit and the rarer sternbergite. The crystal clusters reach sizes of up to 7 mm. For argentopyrit and sternbergite, Jáchymov is the type locality.