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It is now referred to as Mosuo Shi (Mossy Stone), with the best quality being those of pale color, greenish stone hue, and faintly interspersed with gold stars. When ground, its color resembles pale milk, and its taste is bland. There is also Douban Shi (Bean-spotted Stone), which resembles this stone but has black spots on its surface and lacks gold stars.

The current *Tu Jing* (Illustrated Classic) states: "The *Ben Jing* (Divine Farmer's Materia Medica) records that it is sweet and neutral in nature, treating metal wounds and fractures, and promoting tissue regeneration. It is now said to be salty and cold in nature, reducing swelling and toxic carbuncles, which differs from the description in the *Ben Jing*. I suspect it may be a different substance." Upon detailed examination, the preceding thirty-six characters remain unclear; regarding the character "yun" (say/refer) mentioned below, it is unknown what source or location is being referenced.

It originates from Mount Emei, appearing clear and transparent like Shuijing (Rock Crystal). Under sunlight, it displays five-colored light, resembling the aureole of Bodhisattva Samantabhadra at Mount Emei, hence its name. It is rarely used by physicians today.

The term "Xie" (powder/dust) is added to "Jin" (Gold) to indicate that it has already been ground into a usable powder, similar to the meaning of Yujiang (Jade Paste). The *Ben Jing* does not explain "Xie" as unprocessed material; rather, it implies that the gold must be cooked, refined, and forged into thin sheets before it can be ground into powder for medicinal use. Tao Hongjing stated: "When using Silver Xie, mix it with Shuiyin (Mercury) to form a paste." If it were not forged into thin sheets, how could it be mixed with mercury to form a paste? The omission of discussion on Gold Xie is also a deficiency in the text. Raw Jin (Native Gold) is toxic and can even cause death, which remains difficult to understand. For those poisoned by it, only Zhegu Rou (Partridge Meat) can serve as an antidote. If not processed into powder by forging, it cannot be used. Lumps of Jin found in mountains may extend hundreds of feet; when accompanied by mineral stones, the stones are brownish, with one end looking scorched black, indicating the presence of visible gold. Its color is deep reddish-yellow. Fumin (Bran-like Gold) is obtained by washing and sifting river sand and water, appearing pale yellow. These all belong to raw Jin and should be smelted and refined upon acquisition. Fumin has less loss during processing, whereas lump Jin has greater loss. For medicinal use, lump Jin should be employed; its deeper color indicates sufficient Jin Qi (Metal Energy). I further guard against those produced through wrapping techniques or alchemical transmutation; such substances lack the vital energy of natural creation.

For instance, Zhang Yongde of the Song Dynasty, courtesy name Baoyi, was from Bingzhou. During the Five Dynasties period, he served as the Military Governor of Lu. In the second year of Chunhua, he was transferred to Bingzhou. Initially residing in Suiyang, he treated a neighboring scholar who was bedridden with illness, successfully curing him. One day, the scholar requested five liang of Mercury from Zhang Yongde. Zhang placed it in a cauldron and boiled it to produce Middle Gold. Zhang earnestly requested the method, but the scholar replied, "You will attain high status; I do not withhold this secret, but I fear it may diminish your fortune." Bi Sheng, a smith, stated: During the Xiangfu era, he worked in the imperial palace forging gold for the Daoist priest Wang Jie. He used iron to create gold, forming over a hundred liang into a cake, which was then divided into eight segments, known as Yazui Jin (Crow-beak Gold). Freshly taken out of the furnace, its color was still black. From this, we can see that such substances are made using Mercury and Iron with specific drugs, not formed by natural creation; thus, their therapeutic effects would inevitably differ. Specifically, when Huimin Ju (Public Welfare Bureau) prepared Zixue (Purple Snow), they used Gold, presumably borrowing its natural Jin Qi. However, they avoided Tin. Furthermore, gold from the southeast tends to be darker in color, while that from the southwest is lighter, likely due to geographical suitability. For medicinal purposes, the darker variety is preferred. However, if combined with Yuganzi (Phyllanthus emblica fruit), the texture becomes softer, demonstrating mutual interaction.