Acanthite
Date Mine
Kimonbetsu village, Date city, Iburi branch, Hokkaido, Japan
Source for Silver
Field of view: 2 mm. Acanthite associated with quartz. The black grain with a metallic luster at the right is acanthite. The surrounding white host is gangue quartz. The opaque white parts are fine quartz crystals, and the transparent parts are larger crystals. The brown part is a limonite crust.
Recovered from a quartz vein of a hydrothermal Au-Ag deposit associated with andesitic-dacitic tuff breccia, eruption products of a submarine caldera. Formed in the late Miocene (10 Ma).