[Japanese Famous Stone] Bracelet Ako Stone <Hyogo Prefecture> Light Gray Round [br-g8228]

◇What is "AKO Stone"?

A time when the Japanese archipelago was not yet in its current location and was connected to the Eurasian continent by land.
82 million years ago, a volcano in Ako erupted and formed a caldera.
As time passes and the rock weathers, the caldera disappears and becomes a cauldron.
The Cauldron covers a wide area, stretching 21km east to west and 16km north to south, from Okayama Prefecture in the west to Tatsuno City in the east.
This cauldron contains layers of welded tuff and plutonic rock.
Welded tuff is a volcanic rock, and plutonic rock was originally igneous rock, but the two have different origins, and research by AIST has revealed that Ako was originally a volcano.
Therefore, the stones found here are of mixed composition.
Atago Shrine is located in a place that protects the evil spirits of Ako Castle, and it was built on top of the cauldron.Ako Castle was the castle of the Asano clan and is also famous for the Ako Roshi.
Atago Shrine is the god of fire, and Atago Daigongen is a syncretic war god.
It is unclear whether it was a coincidence that the god of fire was enshrined here at a time when it was not even known that this place was a volcano.