Ingredient Mineral (矿物 kuàng wù)

Ci Shi

Magnetite · 磁石

Fe₃O₄ (ferriferrous oxide, magnetite mineral of the spinel group) · Magnetitum

Also known as: Ling Ci Shi (灵磁石), Xi Tie Shi (吸铁石), Huo Ci Shi (活磁石),

Ci Shi (Magnetite) plant

Images shown are for educational purposes only

Magnetite is a mineral substance used in Chinese medicine to calm the mind, ease dizziness and ringing in the ears, and help with shortness of breath caused by weakness. It works by settling overactivity in the body and supporting the Kidneys, Liver, and Heart. It is especially helpful for people experiencing anxiety, poor sleep, tinnitus, blurry vision, or asthma related to underlying deficiency.

Category Substances that anchor and calm the Spirit (重镇安神药)
Therapeutic focus Sleep and Anxiety Support Ear and Hearing Health Eye Health and Vision Respiratory Health

TCM Properties

Temperature

Cold

Taste

Acrid / Pungent (辛 xīn), Salty (咸 xián)

Channels entered

Heart, Liver, Kidneys

Parts used

Mineral (矿物 kuàng wù)

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Educational content • Consult qualified TCM practitioners for diagnosis and treatment

What This Ingredient Does

Every ingredient has a specific set of actions — here's what Ci Shi does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Ci Shi is primarily used to support these areas of health:

Sleep and Anxiety Support Ear and Hearing Health Eye Health and Vision Respiratory Health

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Ci Shi performs to restore balance in the body:

Anchors and Calms the Spirit Calms the Liver and Subdues Yang Opens the Ear Orifices and Brightens the Eyes Aids the Kidneys in Grasping Qi Benefits the Kidneys

How these actions work

'Anchors and calms the spirit' means Ci Shi uses its heavy, mineral weight to settle an agitated mind. Because it is physically dense and salty-cold in nature, it pulls overactive Qi downward, calming restlessness, palpitations, insomnia, and even convulsions or epilepsy. This is the principle of using heavy substances to overcome fright and anxiety (重可去怯). It is especially suited when the spirit is disturbed because Yin is deficient and Yang floats upward.

'Subdues Liver Yang' means Ci Shi pulls excessive upward-rising Yang back down. When the Liver and Kidney Yin are depleted, Yang rises unchecked, causing dizziness, headaches, irritability, and a sensation of pressure in the head. Ci Shi's cold, sinking nature and its affinity for the Liver and Kidney channels make it effective at anchoring this floating Yang.

'Improves hearing and brightens the eyes' reflects the classical understanding that the Kidneys open to the ears and the Liver opens to the eyes. When Kidney essence is insufficient, hearing declines, producing tinnitus or deafness. When Liver Blood is deficient, vision becomes blurry. By nourishing the Kidneys and calming the Liver, Ci Shi addresses both sensory impairments at their root.

'Aids the Kidneys in grasping Qi' refers to the Kidney's role in receiving Qi sent down from the Lungs. When the Kidneys are too weak to anchor this Qi, it rebels upward, causing shortness of breath and asthma that worsens with exertion. Ci Shi's heavy, descending nature helps draw Qi back down into the Kidneys, relieving this type of deficiency-based wheezing.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Ci Shi is used to help correct these specific patterns.

Why Ci Shi addresses this pattern

In Liver Yang Rising, Yin in the lower body is depleted while Yang flares upward unchecked, causing headaches, dizziness, irritability, and tinnitus. Ci Shi is cold, salty, and heavy. Its salty flavour enters the Kidneys to protect the root Yin, while its heavy mineral weight physically drags the floating Yang back down. Its cold nature also cools the excess heat that accompanies the rising Yang. It enters both the Liver and Kidney channels, directly addressing the axis where this pattern originates.

A practitioner would look for one or more of these signs

Dizziness

Dizziness and vertigo from Yang rising to the head

Headaches

Headache, often at the vertex or temples

Tinnitus

Ringing in the ears

Irritability

Irritability and restlessness

Commonly Used For

These are conditions where Ci Shi is frequently used — but only when they arise from the specific patterns it addresses, not in all cases

Arises from: Liver Yang Rising Liver Blood and Kidney Yin Deficiency

TCM Interpretation

In TCM, the ears are the sensory opening of the Kidneys. When Kidney Essence is depleted through ageing, overwork, or chronic illness, the ears lose their nourishment and tinnitus develops. In many cases, Kidney Yin deficiency also allows Liver Yang to rise unchecked, and this ascending Yang further disturbs the ears, producing louder or higher-pitched ringing. TCM sees tinnitus not as a local ear problem but as a reflection of imbalance in the Kidney-Liver axis.

Why Ci Shi Helps

Ci Shi is one of the most classically associated herbs for tinnitus. Its salty flavour specifically enters the Kidney channel, supporting Kidney Essence and strengthening the organ that governs hearing. Its heavy, descending nature pulls floating Yang back down, addressing the Liver Yang component of many tinnitus cases. Classical texts note that Ci Shi 'enters the Kidneys and nourishes the Kidney organ; the Kidneys open to the ears, therefore it treats deafness.' It is commonly combined with Kidney-nourishing herbs like Shu Di Huang and Shan Zhu Yu in formulas such as Er Long Zuo Ci Wan.

Also commonly used for

Hearing Loss

Gradual age-related or Kidney deficiency type

Dizziness

From Liver Yang rising

Palpitations

From Heart spirit disturbance

Blurry Vision

From Liver-Kidney Yin deficiency

Epilepsy

Seizures from Phlegm-Heat disturbing the Heart

Anxiety

From Yin deficiency with floating Yang

Hypertension

Liver Yang rising type with headache and dizziness

Ingredient Properties

Every ingredient has an inherent temperature, taste, and affinity for specific channels — these properties determine how it interacts with the body

Temperature

Cold

Taste

Acrid / Pungent (辛 xīn), Salty (咸 xián)

Channels Entered

Heart Liver Kidneys

Parts Used

Mineral (矿物 kuàng wù)

Dosage & Preparation

These are general dosage guidelines for Ci Shi — always follow your practitioner's recommendation, as dosages vary based on the formula and your individual condition

Standard dosage

9–30g

Maximum dosage

Up to 50g in decoction under practitioner supervision for short-term use, with mandatory pre-decoction of at least 20-30 minutes. Some classical sources cite up to one liang (approximately 30-50g). Do not exceed 3g when taken as pills or powder.

Dosage notes

Use lower doses (9–15g) for calming the spirit and settling anxiety. Use moderate to higher doses (15–30g) for subduing Liver Yang and treating dizziness or tinnitus. For anchoring Kidney Qi to treat wheezing, moderate doses (15–30g) are typical. When taken as pills or powder (not decocted), the dose must be much smaller (1.5–3g) because the undecocted mineral is extremely difficult to digest. Raw (生磁石) is preferred for calming the spirit and subduing Yang; vinegar-calcined (煅磁石) is preferred for benefiting hearing and vision, and for anchoring Qi to stop wheezing, as calcination makes the active iron compounds more bioavailable. Always combine with Shen Qu (medicated leaven) when using in pill or powder form to protect the Stomach and aid digestion of the mineral.

Preparation

Must be decocted first (先煎, xiān jiān). Crush or break into small pieces before adding to the decoction pot, then boil for 20–30 minutes before adding the other herbs. This extended decoction time is necessary because the dense mineral does not release its active constituents easily. The calcined form (煅磁石, duàn cí shí) is prepared by heating magnetite until red-hot, then quenching in vinegar (醋淬), repeating until the stone becomes brittle and crumbly. This process makes the mineral easier to crush, increases solubility of iron and calcium, and significantly reduces arsenic and other harmful trace element content.

Processing Methods

In TCM, the same ingredient can be prepared in different ways to change its effects — here's how processing alters what Ci Shi does

Processing method

The raw magnetite is heated red-hot in a furnace, then immediately quenched in vinegar (醋淬 cù cuì). This is typically repeated once or twice. The ratio is approximately 30kg of vinegar per 100kg of magnetite. After quenching, the stone is dried and ground into coarse powder.

How it changes properties

Calcination with vinegar quenching makes the magnetite brittle and easier to crush into powder for use in pills and powders. The processed form is stronger at tonifying the Kidneys, grasping Qi, and improving hearing and vision. However, its heavy sedating and spirit-calming properties are somewhat reduced compared to the raw form.

When to use this form

Use the calcined form (Duan Ci Shi) when the primary goal is to improve hearing, brighten the eyes, or aid the Kidneys in grasping Qi for asthma. This is the standard form dispensed in most pharmacies when the prescription simply writes 'Ci Shi' without specifying raw. It is also preferred for pills and powders since raw magnetite is too hard to grind.

Common Ingredient Pairs

These ingredients are traditionally combined with Ci Shi for enhanced therapeutic effect

Zhu Sha
Zhu Sha 2:1 (Ci Shi 60g : Zhu Sha 30g, as in Ci Zhu Wan)

Ci Shi anchors Yang and nourishes the Kidneys while Zhu Sha (cinnabar) sedates the Heart and clears Heart Fire. Together they address the Heart-Kidney axis from both ends: Ci Shi strengthens the Kidney Yin below and Zhu Sha calms the Heart spirit above, creating a powerful combination for settling an agitated mind.

When to use: Palpitations, insomnia, anxiety, epilepsy, and blurred vision caused by Heart-Kidney disharmony with Yin deficiency and floating Yang. This is the core pairing in the classical formula Ci Zhu Wan.

Shi Chang Pu
Shi Chang Pu 2:1 (Ci Shi 60g : Shi Chang Pu 30-45g)

Ci Shi is heavy and descending, pulling Yang downward and nourishing the Kidneys, while Shi Chang Pu (Acorus rhizome) is aromatic and opens the sensory orifices. Together, one opens and the other anchors, creating a complementary strategy for restoring hearing and clearing the mind.

When to use: Tinnitus and deafness due to Yin deficiency or deficiency fire, where the sensory orifices are both undernourished and blocked. Commonly seen in Er Long Zuo Ci Wan variants.

Shu Di Huang
Shu Di Huang 1:4 (Ci Shi 60g : Shu Di Huang 240g, as in Er Long Zuo Ci Wan)

Shu Di Huang (prepared Rehmannia) richly nourishes Kidney Yin and fills the Essence, while Ci Shi anchors Yang and aids the Kidneys. Together they address both the root (Yin and Essence depletion) and the branch (Yang floating upward), making them a comprehensive pair for Kidney-based hearing loss and dizziness.

When to use: Liver-Kidney Yin deficiency with tinnitus, hearing loss, dizziness, and blurred vision. This is the core pairing in Er Long Zuo Ci Wan.

Wu Wei Zi
Wu Wei Zi 1:1 to 2:1 (Ci Shi 15-30g : Wu Wei Zi 6-15g)

Wu Wei Zi (Schisandra fruit) is sour and astringent, with the ability to restrain Lung Qi and tonify Kidney Yin. Ci Shi pulls Qi downward and aids the Kidneys in grasping it. Together they form a 'grasp and restrain' combination that keeps Qi anchored in the lower body.

When to use: Kidney deficiency asthma where Qi fails to descend, with shortness of breath worsened by exertion, and weakness of the low back.

Key Formulas

These well-known formulas feature Ci Shi in a prominent role

Ci Zhu Wan 磁朱丸 King

Ci Zhu Wan (Magnetite and Cinnabar Pill) is the definitive showcase of Ci Shi's spirit-calming and Kidney-nourishing actions. Originally called Shen Qu Wan in the Bei Ji Qian Jin Yao Fang, it pairs Ci Shi with Zhu Sha (cinnabar) and Shen Qu (medicated leaven). Ci Shi serves as King, anchoring floating Yang and nourishing the Kidneys, while Zhu Sha calms the Heart. This formula treats blurred vision, tinnitus, palpitations, and insomnia from Heart-Kidney disharmony.

Er Long Zuo Ci Wan 耳聾左慈丸 Deputy

Er Long Zuo Ci Wan (Deafness Left-Supporting Pill) is the most representative formula for Ci Shi's hearing-improving action. Built on the Liu Wei Di Huang Wan foundation, it adds Ci Shi and Chai Hu (some versions also add Wu Wei Zi and Shi Chang Pu). Ci Shi serves as Deputy, using its heavy descending nature to subdue Yang and its Kidney-entering quality to support the hearing function, complementing Shu Di Huang's Yin-nourishing role as King.

Zi Xue Dan 紫雪丹 Assistant

Zi Xue Dan (Purple Snow Special Pill) is a classical emergency formula for high fever with convulsions and loss of consciousness. Ci Shi serves as Assistant, contributing its heavy spirit-calming and Yang-anchoring properties to help manage the seizures and restlessness that accompany extreme Heat entering the Pericardium.

Comparable Ingredients

These ingredients have overlapping uses — here's how to tell them apart

Long Gu
Ci Shi vs Long Gu

Both Long Gu (dragon bone/fossilised bone) and Ci Shi are heavy mineral substances that anchor Yang and calm the spirit. However, Long Gu is neutral in temperature, astringes and consolidates (stopping sweating, spermatorrhea, and uterine bleeding), and does not specifically nourish the Kidneys. Ci Shi is cold, has a stronger Kidney-nourishing action, aids in grasping Qi for asthma, and specifically improves hearing and vision. Choose Ci Shi when the pattern centres on Kidney deficiency with tinnitus, hearing loss, or asthma; choose Long Gu when the focus is on consolidation and astringency.

Dai Zhe Shi
Ci Shi vs Dai Zhe Shi

Both are heavy mineral substances that subdue Yang and settle fright. Dai Zhe Shi (hematite) focuses on descending rebellious Qi and Liver Fire, making it better for nausea, vomiting, belching, and bleeding from Liver Fire. Ci Shi focuses on nourishing Kidney Yin and protecting the 'True Yin,' making it better when the root is Yin deficiency with floating Yang, tinnitus, or Kidney-type asthma. Dai Zhe Shi descends more aggressively; Ci Shi anchors more gently while also tonifying.

Mu Li
Ci Shi vs Mu Li

Both Mu Li (oyster shell) and Ci Shi anchor Yang and calm the spirit. Mu Li is salty, astringent, and cool, with strong actions to soften hardness (treating nodules, goiter) and astringe (stopping sweating, spermatorrhea). Ci Shi has no astringent or softening actions but specifically nourishes the Kidneys, improves hearing and vision, and aids in grasping Qi. Choose Ci Shi for tinnitus, hearing loss, and Kidney deficiency asthma; choose Mu Li for nodules, excessive sweating, and conditions needing softening and astringency.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Ci Shi

Two main adulterants are documented in both classical and modern sources. Hematite (赤铁矿, alpha-Fe2O3) and limonite (褐铁矿) mixed ores are sometimes sold as magnetite. These look superficially similar — dark, heavy iron-bearing rocks — but lack true magnetic properties and cannot attract iron needles. The Lei Gong Pao Zhi Lun specifically warns against confusing magnetite with "Xuan Zhong Shi" (玄中石) and "Zhong Ma Shi" (中麻石), noting these two stones closely resemble magnetite but cannot attract iron. Zhong Ma Shi is further described as having a reddish skin at its core and a rough texture; ingesting it can reportedly cause severe, untreatable sores. The simplest authenticity test is to check for magnetic attraction to iron: genuine Ci Shi readily attracts iron needles and filings, while substitutes do not.

Educational content — always consult a qualified healthcare provider or TCM practitioner before using any ingredient.

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Ci Shi

Non-toxic

Ci Shi is classified as non-toxic in the Chinese Pharmacopoeia and is considered one of the safest mineral medicines. The Ben Cao Jing Shu specifically notes that while "all mineral medicines are toxic and unsuitable for long-term use, magnetite alone possesses a balanced, harmonious nature." However, raw magnetite ore may contain trace amounts of arsenic and other heavy metals (manganese, chromium, strontium, titanium) depending on its geological origin. Calcination with vinegar (煅醋淬) significantly reduces arsenic content — by approximately 5 to 25 times compared to the raw mineral — and also reduces levels of other harmful trace elements. The main clinical safety concern is not chemical toxicity but rather the physical difficulty of digesting a dense mineral substance, which can burden the Spleen and Stomach and cause abdominal discomfort, especially in pill or powder form.

Contraindications

Situations where Ci Shi should not be used or requires extra caution

Caution

Spleen and Stomach deficiency with weak digestion. Ci Shi is a heavy mineral substance that is difficult to digest and can burden the gastrointestinal tract, potentially causing nausea, abdominal discomfort, or poor appetite in those with pre-existing digestive weakness.

Caution

Pregnancy. As a heavy, descending mineral substance, Ci Shi should be used with caution during pregnancy due to its strong downward-directing properties.

Caution

Long-term continuous use without breaks. Classical sources warn that heavy mineral substances can injure Qi over time. The Ben Cao Cong Xin states it should only be used temporarily, not for prolonged periods.

Caution

Taking as pills or powder in excessive doses. When not decocted, the mineral particles are especially hard to digest and can accumulate in the digestive tract, causing abdominal pain.

Caution

Patterns of pure cold or Yang deficiency without floating Yang or excess Heat. Ci Shi is cold in nature and its heavy, descending properties are inappropriate when Yang is already deficient and not rising upward.

Classical Incompatibilities

Traditional Chinese pharmacological incompatibilities — herbs or substances to avoid combining with Ci Shi

Ci Shi does not appear on the Eighteen Incompatibilities (十八反) or Nineteen Mutual Fears (十九畏) lists. However, the Ben Cao Jing Ji Zhu records that Chai Hu (柴胡) serves as its envoy herb (使), it is "averse to" (恶) Mu Dan Pi (牡丹) and Mang Cao (莽草), and it "fears" (畏) Huang Shi Zhi (黄石脂).

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Use with caution during pregnancy. Ci Shi is a heavy, strongly descending mineral substance. While it is not classified as a frank abortifacient or uterine stimulant, its powerful downward-directing and settling properties make it theoretically unsuitable for routine use in pregnancy, as excessive descending action could potentially disturb fetal Qi. Standard Materia Medica references note "pregnant women should use with caution" (孕妇慎用). If clinically necessary during pregnancy, it should only be used under close practitioner supervision at reduced dosage and for short duration.

Breastfeeding

No specific classical or modern contraindication for breastfeeding has been documented. However, as a mineral substance containing iron and potential trace heavy metals, caution is warranted. The heavy metal content (particularly trace arsenic in unprocessed forms) could theoretically transfer into breast milk. If use is clinically necessary during breastfeeding, only properly calcined (煅磁石) material should be used at standard doses for limited duration, under practitioner guidance.

Children

Ci Shi has classical indications for childhood fright-epilepsy (小儿惊痫), suggesting historical paediatric use. However, because it is a heavy mineral that burdens digestion, paediatric doses should be significantly reduced from adult ranges and used only for short courses. Children's immature digestive systems are especially vulnerable to the Spleen-burdening effects of mineral medicines. The calcined form (煅磁石) is preferred for children as it is easier to digest. Must always be decocted first (先煎) when used in paediatric formulas. Not suitable for infants or very young children except under specialist supervision.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Ci Shi

No formal drug interaction studies have been conducted specifically on Ci Shi decoctions. However, given that magnetite (Fe3O4) releases soluble iron compounds during decoction and especially after vinegar calcination, interactions typical of iron-containing substances should be considered:

  • Tetracycline antibiotics and fluoroquinolones: Iron can chelate with these antibiotics in the gut, significantly reducing their absorption and therapeutic effectiveness. Separate administration by at least 2 hours.
  • Levothyroxine (thyroid hormone): Iron reduces levothyroxine absorption. Separate by at least 4 hours.
  • Levodopa and methyldopa: Iron may reduce absorption of these medications.
  • Bisphosphonates (for osteoporosis): Iron can impair absorption. Separate administration timing.
  • Antacids and proton pump inhibitors: These may alter the solubility and absorption of iron from Ci Shi.
  • Iron supplements: Concurrent use could lead to excessive iron intake.

Patients taking any regular medications should consult their healthcare provider before using Ci Shi preparations.

Dietary Advice

Foods and dietary considerations when taking Ci Shi

Avoid drinking strong tea or coffee close to the time of taking Ci Shi, as tannins can bind to iron and reduce its effectiveness. When using Ci Shi for its settling and calming effects, avoid overly spicy, greasy, or heavy foods that tax the Spleen and Stomach, since the mineral already burdens digestion. Easily digestible, warm, cooked foods are preferable during a course of treatment. If digestive discomfort occurs, adding foods that strengthen the Spleen such as congee, cooked grains, and ginger may help.

Botanical Description

Physical characteristics and morphology of the Ci Shi source mineral

Ci Shi (磁石) is not a plant but a mineral substance — specifically, it is the ore of magnetite, a naturally occurring magnetic iron oxide belonging to the spinel family of the isometric (cubic) crystal system. Its primary chemical composition is ferriferrous oxide (Fe3O4), typically containing at least 50% iron, along with trace amounts of silicon, manganese, calcium, aluminium, titanium, chromium, and arsenic.

Magnetite crystals form as octahedra or rhombic dodecahedra, though the medicinal material is usually encountered as irregular, angular block-shaped aggregates rather than well-formed single crystals. The mineral is iron-black to brownish-black in colour with a black streak, a semi-metallic lustre, and is completely opaque. It is notably heavy, very hard (Mohs hardness 5.5–6.5), brittle, and fractures unevenly. Its most distinctive feature is its natural magnetism — high-quality specimens can attract and hold iron needles, nails, or small blades.

Magnetite forms in igneous and metamorphic rocks and is also found in coastal beach sands. Major deposits in China occur in iron ore mining regions across many provinces. The mineral is mined from open-pit or underground operations, then sorted to remove non-magnetic rock impurities.

Sourcing & Harvesting

Where Ci Shi is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Year-round (采无时). Magnetite is a mineral ore that can be mined at any time of year without seasonal restriction.

Primary growing regions

Ci Shi is a mineral (magnetite ore) found in iron-bearing geological formations across China. Major producing regions include Jiangsu, Shandong, Liaoning, Hebei, Guangdong, Anhui, Fujian, Hubei, Sichuan, and Yunnan provinces. Historically, the most prized magnetite came from Cizhou (磁州, in modern Hebei province), which contributed annual tribute-quality specimens and is said to have given the mineral its Chinese name. The Ben Cao Tu Jing notes that Cizhou magnetite was considered the finest, capable of attracting chains of ten or more needles.

Quality indicators

The best quality Ci Shi (known as "living magnetite" or 活磁石/灵磁石) is iron-black in colour with a semi-metallic lustre on fresh surfaces. It should be heavy, hard, and difficult to break. Most importantly, it must have strong magnetic properties — the ability to attract and hold iron needles or small iron objects is the single most important quality test. The stronger the magnetic attraction, the better the medicinal quality. Poor quality specimens (called "dead magnetite" or 死磁石/呆磁石) tend toward a reddish-brown colour, have more pore spaces and impurities, break more easily, and have weak or no magnetic attraction. The cross-section should appear dense and compact. There should be a faint earthy (soil-like) smell and a bland, tasteless quality. Avoid specimens with excessive yellow or brownish discolouration, which indicates contamination or oxidation.

Classical Texts

Key passages from the classical Chinese medical texts that describe Ci Shi and its therapeutic uses

Shen Nong Ben Cao Jing (《神农本草经》)

Original: 「味辛，寒。主周痹风湿，肢节中痛，不可持物，洗洗酸痟，除大热烦满及耳聋。」

Translation: "Acrid flavour, cold nature. Treats widespread impediment from wind-damp, pain in the limbs and joints with inability to hold objects, aching and soreness with a tingling sensation, eliminates great Heat and vexation-fullness, and treats deafness."

Ming Yi Bie Lu (《名医别录》)

Original: 「养肾藏，强骨气，益精除烦，通关节，消痈肿鼠瘘，颈核喉痛，小儿惊痫。」

Translation: "Nourishes the Kidney, strengthens bones, augments essence, eliminates vexation, frees the joints, disperses abscesses and scrofula, treats neck lumps and sore throat, and childhood fright-epilepsy."

Ben Cao Gang Mu (《本草纲目》) — Li Shizhen

Original: 「治肾家诸病，而通耳明目。盖慈石入肾，镇养真精，使神水不外移，朱砂入心，镇养心血，使邪火不上侵。」

Translation: "Treats all diseases of the Kidney, and opens the ears and brightens the eyes. Magnetite enters the Kidney, settles and nourishes the true essence, preventing the 'spirit water' from dispersing outward; Cinnabar enters the Heart, settles and nourishes Heart Blood, preventing pathogenic fire from invading upward."

Ben Cao Jing Shu (《本草经疏》)

Original: 「诸药石皆有毒，且不宜久服，独磁石性禀冲和，无猛悍之气，更有补肾益精之功。」

Translation: "All mineral medicines are toxic and should not be taken long-term. Magnetite alone possesses a balanced, harmonious nature without any fierce or aggressive qualities, and furthermore has the ability to supplement the Kidney and augment the essence."

Historical Context

The history and evolution of Ci Shi's use in Chinese medicine over the centuries

Ci Shi is one of the oldest mineral medicines in the Chinese pharmacopoeia, first recorded in the Shen Nong Ben Cao Jing (circa 2nd century CE) where it was classified as a middle-grade (zhong pin) substance. Its Chinese name literally means "loving stone" — an ancient poetic reference to how the stone attracts iron "like a loving mother calling her child" (慈母招子), as explained by Chen Cangqi in the Ben Cao Shi Yi. The alternate character 磁 (magnetic) is a later substitution that became standard.

Ci Shi holds a unique place in the history of science as well as medicine. The Ben Cao Yan Yi by Kou Zongshi (Song Dynasty) contains one of the earliest detailed descriptions of the magnetic compass principle, noting that a magnetized needle "points south, though always slightly east of true south." Li Shizhen in the Ben Cao Gang Mu recorded his own clinical experience using Ci Zhu Wan (Magnetite and Cinnabar Pill) — originally from Sun Simiao's Qian Jin Fang — to successfully treat a scholar's progressive visual deterioration over two months, explaining the formula's mechanism through the Heart-Kidney interaction theory.

The classical grading system for magnetite quality was remarkably precise: the Lei Gong Pao Zhi Lun classified specimens by their iron-attracting power — a piece that could attract one jin (roughly 500g) of iron on all four sides was called "Longevity Sand" (延年沙), those attracting eight liang were "Continuation Stone" (续采石), and those attracting around five liang were simply "magnetite." This classification system reflects how seriously practitioners took the relationship between a mineral's physical properties and its medicinal potency.