味辛、咸，寒，无毒。主周痹风湿，肢节中痛，不可持物，洗洗酸 ，除大热，烦
满及耳聋。养肾脏，强骨气，益精，除烦，通关节，消痈肿鼠 ，颈核喉痛，小儿惊痫，炼
水饮之。亦令人有子。一名玄石，一名处石。生大山川谷及慈山山阴，有铁者则生其阳，采
无时。
柴胡为之使，杀铁毒，恶牡丹、莽草，畏黄石脂。今南方亦有，其好者，能悬吸针，虚
连三、四、五为佳，杀铁物
毒，消金。《仙经》、《丹方》、《黄白术》中多用也。
味咸，温，无毒。主大人小儿惊痫，女子绝孕，少腹寒痛，少精、身重。服之令人有
子。一名玄水石，一名处石。生太山之阳，山阴有铜。铜者雌，玄者雄。
恶松脂、柏子、菌桂。《本经》磁石，一名玄石。《别录》各一种。今案其一名处石，名
既同，疗体又相似，而寒温
铜铁及畏恶有异。俗中既不复用，无识其形者，不知与磁石相类否？
〔谨案〕此物，铁液也，
但不能拾针，疗体如《经方》，
劣于磁石。磁石中有细孔，孔中
黄赤色，初破好者，能连十针，一斤铁刀亦被回转。其无孔，光泽纯黑者，玄石也，不能悬
针也。
味辛、甘，寒、大寒，无毒。主身热，利胃，解烦，益精，明目，破积聚，去三虫
。除营卫中去来大热，结热，解烦毒，止消渴，及中风痿痹。一名立制石，一名肌石，如石
膏，顺理而细。生汉中山谷及卢山，采无时。
滑石为之使，畏麻黄。汉中属梁州，卢山属青州。今出宁州。俗用亦希，《仙经》时须，
亦呼为长理石。石胆一名立
制石，今此又名立制，疑必相乱类。
〔谨案〕此石夹两石间如石
脉，打用之，或在土中重叠而生。皮黄赤，肉白，作针理文，全不似石膏。汉中人取酒浸
服，疗癖，令人肥悦。市人或刮去皮，以代寒水石，并以当 石，并是假伪。今卢山亦无此
物，见出襄州西泛水侧也。
[Cishi, Magnetitum]
Pungent and salty in flavor, cold in nature, non-toxic. It primarily treats generalized bi-syndrome (painful obstruction syndrome) caused by wind-dampness, pain in the limbs and joints, inability to hold objects, a sensation of soreness and discomfort in the body, clears severe heat, relieves fullness and irritability, and cures deafness. It nourishes the Kidney organ, strengthens bone qi, benefits essence, eliminates vexation, unblocks joint orifices, dissipates carbuncles and swellings, scrofula (tuberculous lymphadenitis), cervical masses, and throat pain; treats pediatric convulsions and epilepsy. It should be calcined and taken with water. It also promotes fertility. It is also known as Xuan Shi (Magnetite) and Chu Shi. It grows in deep mountain valleys and on the shady slopes of Ci Mountain; where iron exists, it grows on the sunny slopes. It can be harvested at any time.
Chaihu (Bupleuri Radix) serves as its guiding herb. It neutralizes iron toxicity. It is incompatible with Mudan Pi (Moutan Cortex) and Mangcao (Aconiti Lateralis Preparata Radix), and fears Huangshi Zhi (Kaolin). It is now also found in the south. The best quality can suspend and attract needles; suspending three, four, or five needles is considered optimal. It neutralizes the toxicity generated by iron objects and dissolves gold. It is frequently used in *Xian Jing* (Immortal Classic), *Dan Fang* (Alchemy Formulas), and *Huang Bai Shu* (Alchemical Arts).
[Xuanshi, Magnetitum Impurum]
Salty in flavor, warm in nature, non-toxic. It primarily treats convulsions and epilepsy in adults and children, sterility in women, cold pain in the lower abdomen, scanty essence, and heaviness of the body. Taking it promotes fertility. It is also known as Xuanshui Shi (Black Water Stone) and Chu Shi. It grows on the sunny slopes of Mount Tai, while copper is found on the shady slopes. Those containing copper are female (yin); those without copper (pure black) are male (yang).
It is incompatible with Songzhi (Pinus Resin), Baizi (Platycladi Semen), and Ronggui (Cinnamomi Ramulus). In *Shennong Bencao Jing*, Cishi is named Xuan Shi. *Mingyi Bielu* lists them as two different substances. Currently, we examine that both share the name Chu Shi, have similar names and therapeutic effects, but differ in their thermal nature (cold vs. warm) and incompatibilities regarding copper and iron. Since they are no longer commonly used by the public, few recognize their appearance, and it is unknown whether they are similar to Cishi.
[Imperial Commentary]: This substance is congealed liquid iron. It cannot attract needles. Its therapeutic effect is as described in *Jing Fang* (Classic Formulas), but inferior to Cishi. Cishi contains fine pores; inside the pores, the color is yellowish-red. When freshly broken, high-quality Cishi can attach ten needles, and even a one-jin iron knife will rotate towards it. Those without pores, with a glossy pure black appearance, are Xuanshi, which cannot suspend needles.
[Lishi, Talcum]
Pungent and sweet in flavor, cold and severely cold in nature, non-toxic. It primarily treats bodily fever, benefits the Stomach, resolves vexation, benefits essence, brightens the eyes, breaks up accumulations and masses, removes three types of parasites. It clears severe heat coming and going from the Ying and Wei levels, resolves stagnant heat, relieves toxic vexation, stops thirst-quenching disease (xiao-ke), and treats flaccidity and bi-syndrome resulting from wind-stroke. It is also known as Lizhi Shi (Stabilizing Stone) and Jishi. It resembles Gypsum Fibrosum, with smooth and fine grain. It grows in the valleys of Hanzhong and Mount Lu. It can be harvested at any time.
Huashi (Talcum) serves as its guiding herb. It fears Mahuang (Ephedrae Herba). Hanzhong belongs to Liangzhou, and Mount Lu belongs to Qingzhou. It is currently produced in Ningzhou. It is rarely used by the common people, though occasionally required in *Xian Jing*. It is also called Changli Shi (Long Grain Stone). Shidan (Melanteritum) is also named Lizhi Shi. Now this stone is also called Lizhi; suspicion arises that they must be confused as similar categories.
[Imperial Commentary]: This stone lies between two layers of rock like a stone vein, and is used after crushing. It may grow overlapping in the soil. The skin is yellowish-red, the flesh is white, presenting needle-like grain patterns, completely unlike Gypsum Fibrosum. People in Hanzhong soak it in wine and take it internally to treat fixed masses (pi), making the person plump and radiant. Merchants sometimes scrape off the skin to substitute for Hanshui Shi (Gypsum Album) and pass it off as Xuanshi; these are all counterfeit. Mount Lu no longer produces this substance. It is seen being produced near Fan River in the west of Xiangzhou.