Synonym
Litharge, Talc, Chalk, and Talcum (from "Bailu"), Calamine (from "Yao Xing Lun"), Brittle Stone, and Retentive Stone (from "Shiyao Er Ya"), Picture Stone (from "Bencao Yan Yi").
Source
A blocky body of talc, a silicate mineral.
Mineral form
Talc, monoclinic crystal system. Crystals are hexagonal or rhombic plate-like, but perfect crystals are rarely seen, usually occurring as dense granular or scaly masses. Color is pale green, white, or gray. Streak is white or pale green. Greasy luster. Cleavage surfaces show pearl-like appearance. Semi-transparent to opaque.
Fully cleaves along the basal plane. Hardness 1, specific gravity 2.7-2.8. Soft in texture. Slippery to the touch. Blocky talc can be sawn into any shape, and thin slices can be bent, but lack elasticity. Mainly found in metamorphic rocks, limestone, dolomite, magnesite, and shale.
Harvest
After harvesting, clean off the soil and debris. Or, scrape the talc blocks clean, crush them using a粉碎机, and then sieve through a fine screen to obtain talc powder.
Materials
Flat, oblong, or irregularly shaped pieces, varying in size. Entirely white, eggshell, or cream-colored, with a pearl-like luster, semi-transparent or opaque. Soft and fine, with a smooth feel when touched, the white powder can be scraped off with a fingernail. Odorless, tasteless, with a slightly cool sensation. Prefers to be clean, light blue-white, smooth, and free of impurities. Grown in Jiangxi, Shandong, Jiangsu, Shaanxi, Shanxi, Hebei, Fujian, Zhejiang, Guangdong, Guangxi, Liaoning, and other areas.
Chemical Composition
Primarily magnesium silicate, with 31.7% MgO, 63.5% silicon dioxide, and 4.8% water. Typically, some of the MgO is replaced by FeO. Additionally, it contains impurities such as aluminum oxide.
Yao's therapeutic effects
①Talc powder, due to its small particles and large total surface area, can adsorb a significant amount of chemical irritants or toxins. Therefore, when sprinkled on the surface of inflamed or damaged tissues, it can provide protection. Internally, it not only protects the inflamed gastrointestinal mucosa, but also exerts an antiemetic and antidiarrheal effect, while also preventing the absorption of toxins in the gastrointestinal tract. However, talc is not entirely harmless and can cause granulomas in areas such as the abdomen, rectum, and vagina.
② Antibacterial action: Using the plate method, the culture medium containing 10% talc can control typhoid and paratyphoid A bacteria; the disc method has only a slight antibacterial effect on meningococcus.

Talc powder masterbatch for paint-grade can significantly enhance the rigidity and creep resistance, hardness and resistance to surface scratching, thermal resistance and thermal deformation temperature of plastic products. Industrial-grade talc with a fine particle size can also improve the impact strength of plastic products. Moreover, it provides lubrication, acts as a flow promoter, and enhances the processability of plastic during manufacturing.
Industrial talc powder is commonly used as a filler in polypropylene. Industrial talc powder features a lamellar structure with a thin sheet-like configuration. Therefore, finely ground industrial talc powder can serve as a reinforcing filler for polypropylene. Adding industrial-grade talc masterbatch to the polypropylene modification system not only significantly enhances the rigidity, surface hardness, thermal creep resistance, electrical insulation, dimensional stability, and impact strength of polypropylene products but also improves the impact resistance. The addition of a small amount of industrial talc powder to polypropylene can act as a nucleating agent, increasing the crystallinity of polypropylene. This enhances the mechanical properties of polypropylene and, by increasing its crystallinity and refining the grain structure, also improves its transparency.