kaname-ishi
Holy stones which can calm earthquakes. The word 'Kaname-ishi' is often translated as 'keystone.'
In Touhou, Hinanawi Tenshi is associated with an atypically floating keystone which has shimenawa (sacred ropes) tied around it.
For the similarly named Pokemon items, see Mega Stone or Odd keystone.
See also
The following tags are aliased to this tag: keystone (learn more).