What granite is
Granite, kakōgan, is a plutonic rock formed as magma cools slowly deep underground, made of coarse interlocking grains of quartz, feldspar and mica. It usually shows dark grains scattered on a white or grey ground, and is also called mikage-ishi. The Ministry of Land, Infrastructure, Transport and Tourism's guide to stone structures gives its water absorption as about 0.1 to 0.5 per cent, far less than andesite, sandstone or tuff.
Hard and durable, it has long been used for gateposts, boundary walls, bridges, retaining walls, foundations and monuments. It is laborious to work, however, and takes much more time to cut and finish than soft tuffs such as Ōya stone or Shakudani stone. Finishes include edokiri, dressed flat; kobudashi, a flat margin around a raised centre; and Bishan-tataki, a finely pitted surface.
Reading the records and the stone
Records combine the material with the finish, as granite or granite with edokiri dressing. The gateposts of the former Hirata family house in Yokkaichi, Mie, are of granite with raimon carved beneath the cornice of the capitals. The stone bridge before the memorial to Nozaki Buzaemon in Kurashiki, Okayama, uses granite finished by bishan pitting. The walls of the Sato family house in Ichinoseki, Iwate, have a lower part of dressed granite, an upper part of pitted tuff and a coping, putting the hard granite below and the soft tuff above. The former gateposts of Iwazu High School in Okazaki, Aichi, have square granite shafts in kobudashi finish.
On site, look for a coarse texture of white, grey and black grains. The finish changes the look of the stone greatly, so read it together with the finishing term in the record.
References
- 旧平田家住宅門柱｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/heritage/detail/101/00010824
- 野﨑武左衛門翁旌徳碑石橋｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00004180
- 佐藤家住宅正門及び石塀｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00003030
- 愛知県立岩津高等学校正門旧門柱｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00011715
- 河川の景観形成に資する石積み構造物の整備に関する資料｜国土交通省
- https://www.mlit.go.jp/river/shishin_guideline/kankyo/stone-structure/s-1.pdf
Last verified: 2026.09.27