It is called itaishi (stone tablet) sotoba (a tall, narrow wooden tablet set up behind a grave for the repose of the dead) or itaishi toba and especially Musashi-style itahi which is typically imaged is called ao-ishi (a generic name for a blue green stone of chlorite schist much used in gardens) toba as it is made by processing pieces of chrolite schist produced in Chichibu.
板石卒塔婆、板石塔婆と呼ばれ、特に典型的なものとしてイメージされる武蔵型板碑は、秩父産の緑泥片岩を加工して造られるため、青石塔婆とも呼ばれる。