noun
Refers to the chemical element carbon, or carbon-based materials such as carbon paper, carbon fiber, etc.
カーボンはダイヤモンドの主成分です。
Carbon is the main component of diamonds.
この書類はカーボンで複写されています。
This document is copied using carbon paper.
炭素 is the native Japanese word for the chemical element carbon, used in scientific contexts. カーボン is the loanword, more common in everyday and commercial contexts (e.g., carbon paper, carbon fiber).
Loanword from English 'carbon'.