石灰岩(せっかいがん)

せっかいがん
noun
limestone
academictechnicalsciencenature
1. a sedimentary rock composed mainly of calcium carbonate, usually formed from the accumulated shells and skeletons of marine organisms, and widely used as a building stone and as raw material for cement, glass, and lime; limestone
A common sedimentary rock whose main component is calcium carbonate (CaCO3). Most natural limestone forms on the ocean floor from the gradual accumulation and compression of the shells of corals, foraminifera, and other marine organisms. When exposed to slightly acidic groundwater over long periods, limestone dissolves to form distinctive landscapes full of caves, sinkholes, and underground rivers (カルスト地形(ちけい)). Japan has several famous limestone areas, including 秋吉台(あきよしだい) in Yamaguchi and 平尾台(ひらおだい) in Fukuoka. Economically, limestone is the raw material for cement and lime and is one of the few mineral resources Japan produces in surplus.
この山(やま)は石灰岩(せっかいがん)でできている。
This mountain is made of limestone.
石灰岩(せっかいがん)はセメントの原料(げんりょう)になる。
Limestone is used as a raw material for cement.
石灰岩(せっかいがん)が雨水(あまみず)に溶(と)けて鍾乳洞(しょうにゅうどう)ができる。
Limestone dissolves in rainwater, forming limestone caves.
石灰岩(せっかいがん)は、大昔(おおむかし)の海(うみ)に住(す)んでいた生物(せいぶつ)の殻(から)や骨(ほね)が積(つ)み重(かさ)なってできた岩石(がんせき)だ。
Limestone is a rock formed from the accumulated shells and bones of creatures that lived in ancient seas.

Composed of 石灰(せっかい) (lime, calcium oxide / calcium hydroxide) + 岩(がん) (rock). Literally 'lime rock,' referring to the fact that limestone is the raw material from which lime is produced when heated.

Common collocations

Related words

  • 石灰(せっかい): lime — the processed form (calcium oxide or calcium hydroxide) obtained by heating limestone.
  • 大理石(だいりせき): marble — limestone that has been recrystallized by heat and pressure (metamorphosed); used for sculpture and decorative stone.
  • 鍾乳洞(しょうにゅうどう): limestone cave, stalactite cave — formed by the dissolution of 石灰岩(せっかいがん).
  • 鍾乳石(しょうにゅうせき): stalactite — the hanging mineral formation found in limestone caves.
  • カルスト地形(ちけい): karst topography — the distinctive landscape of sinkholes, caves, and rock towers produced when limestone is eroded by slightly acidic water.
  • 炭酸カルシウム(たんさんかるしうむ): calcium carbonate — the main chemical component of limestone.

Similar words (ROCK TYPES)

  • 花崗岩(かこうがん): granite — an igneous rock; unrelated in formation.
  • 砂岩(さがん): sandstone — another sedimentary rock, but formed from sand rather than calcium carbonate.
  • 玄武岩(げんぶがん): basalt — an igneous rock formed from volcanic lava.

Economic note

Limestone is one of the very few mineral resources Japan produces in abundance. It is quarried in large quantities for cement, steelmaking, and agricultural lime, and famous limestone areas such as 秋吉台(あきよしだい) and 平尾台(ひらおだい) are also popular tourist destinations.

Related Words

Related: 大理石(だいりせき) (marble)
Related: 鍾乳洞(しょうにゅうどう) (limestone cave, stalactite cave)
Related: 鍾乳石(しょうにゅうせき) (stalactite)
Compare: 砂岩(さがん) (sandstone)
Compare: 玄武岩(げんぶがん) (basalt)
general
Added 2026.4.12 9:56 · Revised 2026.9.2 13:02
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