English Name

Serpentine

Definition

Jahar Mohara is Serpentine, a hydrous silicate of Magnesium [Mg6(Si4O10)X(OH)8 ]. This is also known as Green Marble in trade.

Synonyms

Samskrta : Jaharamoharā

Regional Name

English - Serpentine, Green Marble, Hindi - Jaharamoharā, Telugu - Salagrama silā, Urdu - Zahar Mohra, Hajr-us-sum, Fad Zahr Madani, Hajrul-behr (N.F.U.M.)

Broad Classification

Hydrous magnesium silicate

Origin and occurrence:

Jahar Mohara results from the alteration, either during metamorphism or by late-stage hydrothermal action at temperatures below 4000, of rocks rich in magnesium, containing olivine, pyroxene or amphibole. Magnetite usually accompanies this alteration. Some serpentine occurs as large rock masses generally referred to as serpentinites. Nickel in minor amount is generally present in Jahar Mohara. A little amount of Calcium, Iron and Aluminium may also be present. In India, Jahar Mohara occurs mostly in metamorphic terrains of Rajasthan, Karnataka, Jharkhand, Madhya Pradesh and Andhra Pradesh. In Rajasthan, it occurs abundantly in Udaipur and Dungurpur districts.

Physical Properties

Nature : Crystalline, coarse grained, soapy feel, Colour : Blackish green, Streak : Colourless, Cleavage : Perfect, Fracture : Conchoidal, Lustre : Greasy, Tenacity : Tough, Transparency : Translucent, Hardness : 3.5 to 5, Sp. Gr. : 2.5 to 2.7

Optical Properties:

Bi-axial, negative, weakly birefringent with R.I. 1.546 to 1.554 (Appendix- 2).

Chemical Properties:

Effect of Heat: Take about 1 g powdered sample of Jahar Mohara in open test tube. Heat the test tube at around 5000. The sample gets decomposed and gives off a little water. Assay:

• Should contain not less than 30% magnesium oxide when analysed by gravimetric method (Appendix-3.1.6).
• Should contain not less than 30 % Silica (SiO2), not less than 5% Ferric oxide (Fe2O3) and not less than 5% calcium oxide (CaO) when analysed by gravimetric method (Appendix -3.1).

Heavy metals and Arsenic: Jahar Mohara should not contain more than the  stated limits for the following: - Arsenic = 2 ppm and Cadmium = 3 ppm (Appendix-3.2). Other Elements : May contain the following within ± 20% of the stated limits:- 0.15 % Nickel when analysed by Atomic Absorption Spectrophotometer (Appendix-3.2.2).

Śodhana

Shall not be used in formulations without subjecting it to śodhana. Śodhana: [Ref. Rasatantrasāra Siddha Prayoga Sangraha, Part-1, Page 73 ] i) Jahar Mohara : 1 part ii) Go-dugdha : Q.S or Āmalaki rasa Method: Heat Jahar Mohara till it becomes red hot and dip in Go-dugdha or Amalaki rasa for 21 times. Jahar Mohara is used in the form of pisti, the details of which are given in the monograph of pisti.