火成岩(かせいがん)

Composed of 火成(かせい) (fire-formed) and 岩(がん) (rock). One of the three fundamental rock classifications taught in Japanese science education, alongside 堆積岩(たいせきがん) (sedimentary rock) and 変成岩(へんせいがん) (metamorphic rock).

火成岩(かせいがん) is further divided into two main categories depending on where the magma cooled:

• 火山岩(かざんがん) (volcanic rock): cooled quickly at or near the surface, with fine-grained texture
• 深成岩(しんせいがん) (plutonic rock): cooled slowly deep underground, with coarse-grained texture

Common collocations

• 火成岩(かせいがん)の種類(しゅるい): types of igneous rock
• 火成岩(かせいがん)が分布(ぶんぷ)する: igneous rock is distributed
• 火成岩(かせいがん)の成分(せいぶん): composition of igneous rock
• 火成岩(かせいがん)を観察(かんさつ)する: to observe igneous rock

Similar words

• 堆積岩(たいせきがん): sedimentary rock — formed from accumulated sediment over time
• 変成岩(へんせいがん): metamorphic rock — formed when existing rock is transformed by heat and pressure
• 火山岩(かざんがん): volcanic rock — a subcategory of igneous rock that cooled on the surface
• 岩石(がんせき): rock (general term) — broader term for any type of rock