Chichibu Geopark

Basic points

Serpentine is a glossy rock with a dark green color, and it is called jamongan (literally means “snake mosaic rock” in Japanese) because the rock surface looks like snake skin. The rock becomes a beautiful stone material when polished and it is also referred to as “green marble.” Serpentine sourced from Chichibu is used in Japan’s Parliament Building.

Serpentine is prone to be worn down over time and also causes landslides. Even today, people avoid building highways and railways on top of areas containing serpentine.