Long Gu (Dragon Bone / Fossilized Bone)

Official Long Gu (龙骨) is the fossilized bone of ancient mammals such as Hipparion, rhinoceros, deer, cattle and elephant (or fossil ivory). The usual Latin name is Fossilia Ossis Mastodi—not a mythical dragon. Wu Hua Long Gu is the high-grade lot with glazed colored banding, layers and a strong tongue-adhering quality. Duan Long Gu is calcined until red-through, stronger to astringe and generate flesh. Mu Li is oyster shell: salty and slightly cold, calms the Liver and anchors Yang, softens hardness and binds—often paired with Long Gu. Write raw or calcined Long Gu, crush it and decoct first.

Tradition records Long Gu as sweet, astringent and neutral (raw use is sometimes called slightly cold), entering the Heart, Liver and Kidney channels, acting to settle fright and calm the spirit, calm the Liver and anchor Yang, and astringe and secure. Calcined it also astringes damp and closes sores. It is used for palpitations and insomnia, fright-wind and mania, Liver-Yang dizziness, spontaneous and night sweating, emission and flooding discharge, chronic diarrhea, and sores that will not close. Heavy and descending—suited to floating deficient Yang and insecurity with leakage, not to damp-heat accumulation or uncleared excess pathogen.

Raw Long Gu is stronger to settle fright, calm the spirit and anchor Liver Yang—insomnia, seizures and dizziness favor it. Calcined Long Gu is stronger to astringe, secure and generate flesh—sweating, emission, flooding, chronic diarrhea and unhealing sores favor it. The mineral fossil is dense and poorly soluble, so it must be crushed and decocted first for 20–30 minutes before the rest. Calcined powder may be dusted on sores. Lots that do not adhere to the tongue and that smoke and stink when burned are not medicinal.