Metal and Mineral Drugs of Ayurveda
Metals like gold, silver, copper, lead, tin, and iron, sand (balu from river banks), lime and
minerals like red arsenic (manassila), gems (manayah), salts (lavana), and red chalk (gairika)
are indicated as drugs pertaining to earth (bhauma). In Indian metallurgy, the term loha is
often used for metals like gold and silver and minerals containing metals (ores) are called
dhatus. There are seven dhatus: suvarna (gold), rajata (silver), tamra (copper), trapa (tin),
tiksna or ayas (iron), sisa or naga (lead), and vaikrintaka.11 Salts or lavanas are mentioned
under the parthive substances. According to Charaka, there are five salts: sauvarcala,
saindhava, vida, audbhida, and samudra. Mani and ratna, being synonyms for each other,
stand for the modern term “jewel” or “gem.”
Mercury is considered eighth metal in rasa shastra. It earned the supreme position among
the minerals and metals. The learned Acharyas also studied the relation and effects
between these metals and planets over the human body and called them grahanga
navaloha. Metals are grouped as shuddha, sishra, and pooti loha.
The calcined forms of metals that are termed bhasmas in Ayurveda are referred to as
parpams and kushta in Siddha and Unani-tibb, respectively. Kushta literally means to kill;
in medical terms it is detoxifying the toxic properties of a toxic metal.12
Although bhasmas are regarded as chief metal-containing pharmaceuticals of Ayurveda,
there are several other preparations prepared from metals. Some of these pharmaceuticals
are described below.
Bhasma
Animal derivatives such as horns, shells, feathers, and metallic and nonmetallic minerals
are normally administered as bhasmas. A bhasma means an ash obtained though incineration.
The starter material undergoes an elaborate process of purification (shodhana). This
process is followed by the reaction phase, which involves incorporation of some other
mineral and herbal extracts. Then the material in pellet form is incinerated in a furnace.
The end product is expected to be a nontoxic material. Examples include swarn bhasma,
shankha bhasma, and tamra bhasma.
Parpati
These are specialized mercury preparations. The name is derived from the method by
which flakes of the compound are obtained. A black sulfide of mercury is obtained by
mixing purified mercury and sulfur. Other drugs as per the formula are added to this and
mixed well by triturating them in mortar and pestle. A shallow pit is made in fresh cow
dung and a banana leaf is placed. The melted compound is poured onto the leaf and is
covered with another leaf. Fresh dung is spread on it evenly. When it is cooled the flakes
are removed and powdered.
Rasayoga
Rasayogas are compound formulations containing mercury and sulfur (in the form of kajjali)
with other metals or minerals. Most of the ingredients contained in a rasayoga are added
in the form of bhasmas. The final form may be either a pill or powder.
Sindoora
Sindoora are prepared by the elaborate process of sublimation. This procedure is termed
kupipakwa vidhi and the sublimed mineral available on the neck of the sublimation glass
flask is called sindoora. Sindoora preparations are considered to be more potent than bhasma
preparations.
Types of Bhasma
Attempts have been made to classify various bhasmas. They have been classified on the
basis of color and appearance. A more scientific way of classification is on the basis of
dominant metal and mineral group. According to this classification, bhasmas have been
grouped as rajata group (silver), tamra group (copper), loha group (iron), pravala group
(shells), etc. Often two metals and a metal with mineral are the ingredients of bhasmas.
For example, Trivanga Bhasma contains lead, tin, and zinc. The metals yield three different
types of bhasma corresponding to the nature of the ingredient used. They appear as best,
medium, and inferior quality. Mercury is always used as a basic substance in the process
of marana.
Preparation of Bhasma: General Procedures
The name bhasma is generally applied to all metallic and nonmetallic substances that are
subjected to the process of incineration and reduction to ash. Here it is applied to the
metals, minerals, and animal products that are, by special processes, calcinated in closed
crucibles in pits with cow dung cakes (puttam). Bhasmas are generally white, pale, or red.
The color of the preparation primarily depends on the parent material. The following
pharmaceutical steps are used to prepare bhasmas.
Shodhana
In Ayurveda, purification is called shodhana. Shodhana is the process through which the
external and internal impurities of metals and minerals are removed. Chemical purification
is different from medicinal purification. In chemical purification it is only elimination of
foreign matters, whereas in medicinal purification the objects are involved in the
1. Elimination of harmful matter from the drug
2. Modification of undesirable physical properties of the drug
3. Conversion of some of the characteristics of the drug to different stages
4. Enhancement of the therapeutic action
There are two kinds of shodhana. The first type, samanya shodhana (general purification),
is applicable to the large number of metals or minerals as heating the thin sheets of metals
and immersing them in oil (taila), extract (takra), cow urine (gomutra), and other materials.
The second type, Vishesha shodhana (special purification), is applicable only to specific
metals, minerals, and in certain preparations. Vishesha shodhana includes bhavana, svedana,
nirvapana, and mardana.
After shodhana bhasmas become soft and malleable for further processing and their
metallic property is improved. The main apparatus required includes dola yantra, khalva
yantra, and musha yantra. Various procedures employed for shodhana are described below.
When mineral drugs are heated in a furnace in the presence of dravaka, substances
(liqueficants) like alkali and acid release their satva. This is the purest form of any herbal
or mineral drug. All the metals except mercury are found in nature in solid state, and
they all fuse under high temperature to attain a liquid state. When the temperature lowers
they again return to their natural physical form (i.e., in the solid state). But these fused
metals in the presence of some liqueficants do not return into their natural solid state even
when the temperature lowers (i.e., the metals remain in liquid form). This method of
obtaining metals in liquid form is called dravana and the obtained liquid metal is called
druti. Druti holds superior character with respect to efficacy, toxicity, and increased shelf
life than its native metals and retains its fluidity for a longer time with proper preservation.
Shuddhavarta is a particular stage of heating when the fire becomes strong enough to
yield the pure substance (metal, satva). At this time the flame becomes golden yellow.
Marana
Marana is essentially the burning process or calcination. The purified metal is placed into
a mortar and, with a pestle, ground with the juice of specified plants or kashayas, mercury
(in metallic state), or a compound of mercury such as mercury perchloride (sauviram),
mercuric subchloride (ras karpur), cinnabar (ingalekam), or an amalgam of sulfur and
mercury (kajjali) for a specified period of time. The metal that is intended for marana is
known as a primary metal (pradhan dhatu); the other metal, which is taken in small
proportions for the marana of the primary metal, is known as secondary metal (sahaya
dhatu).14 Small cakes (chakrikas) are made with the ground paste of the minerals and dried
under the sun. The size and thickness of the cakes depend on the heaviness of the drug
and size. The heavier the drug, the thinner the cakes. These cakes are dried well under
the shade and placed in one single layer in a mud tray (sharava) and closed with another
such tray; the clay-smeared cloth keeps both the lid and the container in apposition. The
clay-smeared cloth is applied seven times and dried to seal the crucibles properly. A pit
is dug in an open space and half the pit is filled with dried cow dung cakes. The crucibles
are placed in the half-filled pit and are covered with cow dung cakes up to the brim of
the pit. Fire is then ignited on all four sides and in the middle of the pit. When the burning
is over, the contents are allowed to cool completely on their own.
Marana differs with the nature of the substance to be calcinated. For example, organic
substances such as herbs are burnt in open air, whereas inorganic substances such as
metals like rajata (silver) are burnt in closed containers. In either case the end product is
a bhasma of substance taken for marana. For example, the end product in the case of silver
(rajata) is called as rajata bhasma. Marana of inorganic substances is called puta and the
process of marana of herbs in closed freshly made containers is known as puta paka.13
Bhasmas obtained by marana from primary metals together with herbs (mulika) are called
mulika marita bhasma; the ones where the second metal is taken for the marana of primary
metal are called parada (mercury) marita, or talaka (arsenic trisulphide) marita bhasma,
depending upon the second metal used for the purpose. During the process the second
metal would finally volatilize itself at the temperature of marana, leaving behind the bhasma
of primary metal.
Very few metals like copper or iron still bear some impurities after the marana. In such
cases the whole process is repeated until a purified and therapeutically safer product for
internal use is obtained. In addition, a process called amritikarana is done to make these
metals safer. The process consists of heating the product from the marana procedure in
the presence of some herbal materials to improve safety and therapeutic effect. In this
process the required amounts of triphala decoction, cow’s ghritika, and dhatu bhasma are
placed in an iron pot. Mild heat is applied until the medicinal fluids are completely
evaporated. Bhasma that remains at the end of this process is safer and possesses higher
therapeutic efficacy.
