Variegated Long Gu (Smooth fissures, rough layered cross-section like tree rings, interspersed with blue-gray and reddish-brown patterns, tongue adheres with suction, hard, brittle, and fine powder)

[Naming]

Long Gu (Dragon Bone)

 [Source]

Classic of Materia Medica, Miscellaneous Records

 [Common Usage Level]

B

 [Botanical Origin]

Fossilized bones of ancient mammals such as elephants, rhinoceroses, three-toed horses, camels, and antelopes.

 [Characteristics]

(1) Variegated Long Gu (Five-Colored Long Gu): Irregular lumps, occasionally large cylindrical lumps are seen, the cross-section is like tree rings, varying in size. Generally 6~10㎝ long, 6~10㎝ wide, and about 2~3㎝ thick. The whole is light yellowish-white, light grayish-white, or light brownish-yellow, interspersed with blue-gray and reddish-brown patterns, with varying depths and thicknesses. The surface is smooth, with occasional small fissures. The cross-section is mostly rough, hard and brittle, easily peeling off in fragments. It is easily crushed when twisted, has strong hygroscopicity, and has suction when licked with the tongue. It is odorless and tasteless.
(2) Long Gu: Relatively large, the surface is rough white or yellowish-white, relatively smooth, some have longitudinal fissures, or brown stripes and spots, the texture is as hard as stone, the cross-section is uneven, white or yellow, some are hollow, feel fine like a powdery substance, the joints are enlarged, and the cross-section has numerous honeycomb-shaped small holes, sticky to the tongue, odorless.
Calcined Long Gu: Shaped like fragments of raw Long Gu, showing grayish-brown color, soft and brittle.

 [Preparation]

1. Raw Long Gu 2. Calcined Long Gu

 [Identification]

“Those with a bluish-white color are good,” according to *Wu Pu’s Herbal*. “Those that stick to the tongue when licked are good,” and “those with five colors are good,” according to *Zheng Lei Materia Medica*. “Long Gu should be mostly white as the best,” according to *Medical Formula Collection*. “That which sticks to the tongue when licked and has five colors is the best,” according to *Essentials of Materia Medica*. “Long Gu with five colors is good, and white that sticks to the tongue is good,” according to *Concise Handbook of Benevolent Art*. “White ground brocade pattern, that which sticks to the tongue when licked is good,” according to *Essentials of Materia Medica for Preparedness*.
Variegated Long Gu is best when it is light, brittle, layered, becomes soft when exposed to wind, feels powdery to the touch, and has denser red, white, blue, green, yellow, brown, black and other colors. Long Gu is best when it is hard, white, and has strong hygroscopicity. If the cross-section has no hygroscopicity, and it emits smoke and a strange odor when burned, it should not be used for medicinal purposes. Five-Colored Long Gu is of superior quality.
Main differences: Long Gu is in the shape of bones or broken lumps, white or grayish-white, some have textures or spots, the joint cross-section has honeycomb-shaped small holes, and it sticks to the tongue or slightly sticks to the tongue when licked. Variegated Long Gu is cylindrical or irregular lumps, smooth with five-color textures, easily broken, the cross-section has no small holes, and it sticks to the tongue when licked. The two have different sources, so the morphology is slightly different.

 [Identification Terminology]

1. Five-Colored Cloud Layers: The interior of Five-Colored Long Gu, etc., has alternating layers of red, yellow, blue, white, and brown, also known as five-colored patterns.

 [Chapter]

Minerals