（《本经》中品）
【释名】方石（《本经》）、直石（《别录》）、土石（《别录》）、硬石膏（《纲目》）。
【集解】《别录》曰∶长石，理如马齿，方而润泽，玉色。生长子山谷及泰山、临淄，
采无时。弘景曰∶长子县属上党，临淄县属青州。俗方、《仙经》并无用此者。恭曰∶此石
状同石膏而浓大，纵理而长，纹似马齿。今均州辽 山有之，土人以为理石。颂曰∶今惟潞
州有之，如苏恭所说。按《本经》理石、长石二物，味效亦别。又云∶理石似石膏，顺理而
细。陶隐居言，亦呼为长理石。今灵宝丹用长理石为一物。医家相承用者，乃似石膏，与今
潞州所出长石无异，而诸郡无复出理石者，医方亦不见单用，往往呼长石为长理石。
时珍曰∶长石，即俗呼硬石膏者，状似软石膏而块不扁，性坚硬洁白，有粗理，起齿棱，
击之则片片横碎，光莹如云母、白石英，亦有墙壁似方解石，但不作方块尔。烧之亦不粉烂
而易散，方解烧之亦然，但 声为异尔。昔人以此为石膏，以为方解，今人以此为寒水石，
皆误矣。但与方解乃一类二种，故亦名方石，气味功力相同，通用无妨。唐宋诸方所用石膏，
多是此石，昔医亦以取效，则亦可与石膏通用，但不可解肌发汗耳。
【气味】辛、苦，寒，无毒。
【主治】身热，胃中结气，四肢寒厥，利小便，通血脉，明目去翳眇，下三虫，杀蛊毒
。久服不饥（《本经》）。止消渴，下气，除胁肋肺间邪气（《别录》）。
（收录于《神农本草经》中品）
【释名】方石（出自《神农本草经》）、直石（出自《名医别录》）、土石（出自《名医别录》）、硬石膏（出自《本草纲目》）。
【集解】《名医别录》记载：长石，纹理像马齿一样，形状方正且润泽，颜色呈玉色。产于长子县的山谷以及泰山、临淄等地，采集没有固定时间。陶弘景说：长子县属于上党郡，临淄县属于青州。民间医方和道教仙经都没有使用这种药石的。苏恭说：这种石头形状与石膏相同但更厚实巨大，纹理纵向延伸且较长，纹路类似马齿。现在均州辽山有出产，当地人把它当作理石。苏颂说：现在只有潞州有出产，符合苏恭所说的情况。按照《神农本草经》记载，理石和长石是两种药物，味道和功效也不同。书中又说：理石像石膏，顺着纹理生长且质地细腻。陶隐居（陶弘景）说，理石也被称为长理石。现在灵宝炼丹术中将长理石作为一种独立药材。医生们沿用的，则是像石膏那样，与现在潞州所产的长石没有区别，而各郡不再出产理石了，医方中也未见单独使用理石的情况，人们往往把长石称为长理石。
李时珍说：长石，就是俗称的硬石膏，形状像软石膏但块状不扁平，性质坚硬洁白，有粗糙的纹理，边缘起棱如锯齿，敲击后则横向碎裂成片，光泽晶莹如同云母和白石英，也有像墙壁一样的形态类似方解石，只是不形成方块而已。烧灼它也不会粉化烂掉而是容易散开，方解石烧灼也是这样，只是声音不同罢了。古人把它当作石膏，又当作方解石，今人把它当作寒水石，都是错误的。但它与方解石属于同一类下的两个品种，所以也叫方石，气味和功效相同，通用无妨。唐宋时期各方剂中使用的石膏，大多是这个石种，以前的医生也用它取得疗效，那么它可以与石膏通用，只是不能用于解除肌表之邪和发汗罢了。
【气味】辛味、苦味，性寒，无毒。
【主治】身体发热，胃中气机郁结，四肢寒冷厥逆，通利小便，疏通血脉，明目去除眼翳，驱除三种寄生虫，杀灭蛊毒。长期服用可以不觉饥饿（出自《神农本草经》）。治疗消渴症，降气，消除胁肋部和肺间的邪气（出自《名医别录》）。
(Recorded in the Middle Category of *Shennong Bencao Jing*)
[Names] Fangshi (from *Shennong Bencao Jing*), Zhishi (from *Mingyi Bielu*), Tushi (from *Mingyi Bielu*), Yingshigao (from *Bencao Gangmu*).
[Collected Explanations] *Mingyi Bielu* states: Changshi has textures resembling horse teeth, is square and moist in appearance, and has a jade-like color. It grows in the valleys of Changzi County as well as Mount Tai and Linzi. It can be harvested at any time. Tao Hongjing said: Changzi County belongs to Shangdang Commandery, and Linzi County belongs to Qingzhou. Neither common medical prescriptions nor Daoist immortal scriptures use this stone. Su Gong said: This stone resembles Shigao but is thicker and larger; its grain runs longitudinally and is long, with patterns similar to horse teeth. Currently, it is found in Liao Mountain, Junzhou, where locals treat it as Lizhi. Su Song said: Currently, it is only found in Luzhou, consistent with what Su Gong described. According to *Shennong Bencao Jing*, Lizhi and Changshi are two different substances with distinct tastes and effects. The text also states: Lizhi resembles Shigao, with fine grains running along the direction. Tao Yinju (Tao Hongjing) stated that it is also called Changlizhi. In the alchemical practices of Lingbao, Changlizhi is used as a separate substance. What physicians have traditionally used resembles Shigao and is indistinguishable from the Changshi produced in Luzhou today. Since Lizhi is no longer produced in various commanderies and is rarely used alone in medical prescriptions, people often refer to Changshi as Changlizhi.
Li Shizhen said: Changshi is what is commonly known as Yingshigao (Hard Gypsum). Its shape resembles Ruanshigao (Soft Gypsum), but the blocks are not flat. It is hard, white, and pure, with coarse grains and serrated edges. When struck, it breaks transversely into flakes, shining brightly like Yunmu (Mica) and Baishiyin (White Quartz). Some resemble walls and look like Fangjieshi (Siderite), though they do not form perfect cubes. When heated, it does not turn to powder but scatters easily, just like Fangjieshi, differing only in the sound produced. Ancients mistook it for Shigao or Fangjieshi, and moderns mistake it for Hanshuishi (Cold Water Stone); all these are errors. However, since it belongs to the same category as Fangjieshi but is a different variety, it is also named Fangshi. Its taste and efficacy are identical, so they can be used interchangeably without issue. The Shigao used in prescriptions during the Tang and Song dynasties was mostly this stone, and ancient physicians achieved therapeutic results with it. Therefore, it can be used interchangeably with Shigao, except that it should not be used to release the muscle layer or induce sweating.
[Taste and Properties] Acrid, Bitter, Cold, Non-toxic.
[Indications] Fever, stagnation of Qi in the stomach, coldness and reversal in the four limbs, promoting urination, unblocking blood vessels, improving vision and removing eye nebula, expelling three types of parasites, neutralizing gu poison. Long-term consumption prevents hunger (*Shennong Bencao Jing*). Treats xiaoke (wasting-thirst syndrome), directs Qi downward, and eliminates pathogenic factors in the hypochondrium and lungs (*Mingyi Bielu*).