変成岩(へんせいがん)

Composed of 変成(へんせい) (metamorphosis, transformation) and 岩(がん) (rock). The term literally means "changed-form rock," reflecting the process by which existing rock is transformed without melting.

Common examples include 大理石(だいりせき) (marble, from limestone), 片麻岩(へんまがん) (gneiss), and 結晶片岩(けっしょうへんがん) (schist). The transformation occurs through processes called 変成作用(へんせいさよう) (metamorphism), where existing rock is altered by heat from nearby magma, tectonic pressure, or hot mineral-rich fluids.

Common collocations

• 変成岩(へんせいがん)の種類(しゅるい): types of metamorphic rock
• 変成岩(へんせいがん)が形成(けいせい)される: metamorphic rock is formed
• 広域(こういき)変成岩(へんせいがん): regional metamorphic rock
• 接触(せっしょく)変成岩(へんせいがん): contact metamorphic rock

Similar words

• 火成岩(かせいがん): igneous rock — formed from cooled magma or lava
• 堆積岩(たいせきがん): sedimentary rock — formed from accumulated sediment
• 岩石(がんせき): rock (general term) — broader term for any type of rock