Galena

Field of view: 40 mm. Galena in a quartz vein. The boundary between the quartz vein and the host is the bottom face of this specimen. Th dark gray grains along the boundary between the vein and the host are galena. The black ellipsoidal part at the center is siliceous mudstone, a part of the host, in the vein. The white parts are gangue quartz. The green part at the upper right is malachite.

Recovered from a quartz vein of a moderate-temperature hydrothermal deposit in andesitic pyroclastics formed by dacite probably associated with a volcanic activity of a caldera. Formed in the middle Miocene (15 Ma).

Galena from this location was described in 1898.