rubellite
A red or pink variety of tourmaline used as a gemstone. Technical mineralogy term.
Rubellite is a variety of tourmaline and is treated as a gemstone.
トルマリン is the general term for tourmaline, while 紅電気石 specifically refers to the red/pink variety (rubellite).
Compound of 紅 (red) + 電気石 (tourmaline). The exact historical derivation is uncertain; the spelling is conventionally associated with the red variety of tourmaline.