Silver Veins

The cliff face here is marked with diagonal cuts and cracks where veins of silver run through the rock, along with narrow tunnel openings where miners followed those veins deeper into Mt. Sennoyama. Mining began in the mid-1500s using only chisels and hammers. The unusual density of silver in this mountain traces back to volcanic activity about 1.5 million years ago, when a major eruption left behind porous, brittle rock. Geothermal heat drove groundwater through the rock, picking up silver and copper from surrounding sediment before the liquid cooled and solidified in countless cracks. The result was one of the most productive silver deposits in early modern Japan.