red coral (Corallium japonicum)
Refers specifically to the precious red coral species used in jewelry and traditional crafts.
Red coral is often processed into jewelry.
Usually written in katakana; usually written in kana.
Kanji spelling is understandable but less common than the katakana form.
Compound of 赤 (aka, 'red') and 珊瑚 (sango, 'coral'). The katakana spelling アカサンゴ is common for biological names.