Gypsum (Fibrous crystalline aggregate, white-gray, loose and light, easily broken into small pieces, fibrous texture in longitudinal section, silky luster)

【Naming】

Gypsum

 【Source】

Shen Nong’s Herbal Classic, Middle Grade

 【Common Usage Level】

A

 【Botanical Origin】

Hydrated calcium sulfate mineral.

 【Characteristics】

It is a long block or irregularly shaped fibrous crystalline aggregate, varying in size. The overall color is white to grayish-white. Large pieces have flat, lusterless, and textureless upper and lower surfaces. It is heavy, loose in texture, easily broken into small pieces, with a fibrous texture in the longitudinal section, and has a silky luster. It is soft, can be carved or rubbed into powder by hand, odorless, and has a bland taste.
Calcined Gypsum: White small pieces or powder, off-white, lusterless, loose and brittle.

 【Processing】

1. Raw Gypsum 2. Calcined Gypsum

 【Identification】

《名醫別錄》 (Mingyi Bielu – Records of Famous Physicians): “Gypsum, also known as Fine Stone, is best when finely textured and white and lustrous; yellow ones cause strangury.” 《證類本草》 (Zhenglei Bencao – Classified Materia Medica): “Transparent, with a texture like Mica is superior.” 《普濟方》 (Puji Fang – Prescriptions for Universal Relief): “Gypsum… is best when finely textured like jujube needles.” 《本草綱目》 (Bencao Gangmu – Compendium of Materia Medica): “[Da Ming said] Gypsum, transparent, with a texture like Mica is superior.” 《仁術便覽》 (Renshu Bianlan – Handbook of Benevolent Arts): “Gypsum that is soft and white is good.” 《本草新編》 (Bencao Xinbian – Newly Compiled Materia Medica): “Raw is best.” 《藥徵》 (Yao Zheng – Herbal Characteristics): “The way to collect stone medicine is to take the bottom part as the best.” 《本草求真》 (Bencao Qiuzhen – Seeking Truths in Materia Medica): “Take the lustrous white ones as good.” 《本草求真》 (Bencao Qiuzhen – Seeking Truths in Materia Medica): “It is best when it has been aged and as firm as stone.” 《本草述鉤元》 (Bencao Shugouyuan – Elucidating the Fundamentals of Materia Medica): “It is best when you can feel the medicinal energy in your throat.” 《良劣鑑別》 (Lianglie Jianbie – Distinguishing Good and Bad): “It is superior when there are needle-like textures in the longitudinal section and the texture is soft.”
Good quality is indicated by large blocks, white color, translucency, loose texture, fibrous structure, silky appearance in the longitudinal section, and absence of extraneous stones. When burned, it colors the flame pale red.
Transparent Gypsum, a similar product, is in thin sheets to prismatic form; the texture is soft, with a glassy luster; the cleavage fragments resemble Mica flakes. Calcite, white rhombohedral prisms or platy rhombohedra; when crushed, it mostly exhibits oblique fractures with luster.

 【Identification Terminology】

(Modern)
1. Flexibility: Refers to the property of a mineral being able to be cut by an external force without fracturing, such as Gypsum, etc.
2. Streak: The trace left after dragging a mineral across a streak plate is called a streak. Its color is the color of the mineral powder, which is more consistent than the color of the mineral surface and has identification significance.
3. Cleavage: Refers to the property of a mineral to split along a certain crystal direction after being subjected to force, forming a smooth plane. The split plane is called the cleavage plane.
4. Fracture: The fracture surface of a mineral after being subjected to force along a certain crystal direction.

 【Category】

Minerals