Xanthoconite

Field of view: 5 mm. Xanthoconite associated with proustite. The yellow powder is fine crystals of xanthoconite. The red prisms covered with xanthoconite are proustite. The white basement is gangue quartz.

Recovered from an open space of a quartz vein in a hydrothermal Au-Ag deposit associated with rhyolitic tuff breccia, eruption products of a caldera. Formed in the late Miocene (7.2 Ma).

The first xanthoconite from Japan was reported from this location in 1968.