Kasis (Bhasma)

English Name

Ferrous Sulphate


Kasis is Ferrous Sulphate (FeSO4. 7H2O) also known as Green vitriol, Copper as or melanterite mineral.


Samskrta : Kasisaka, Puspakasisa

Regional Name

Bangali - Hirākas, English - Ferrous Sulphate, Green vitriol, Gujarati - Hīrākasī, Hindi - Kasīs, HīraKasīs, Kannada - Kaasisa, Annabedi, Malayalam - Turusi, Turus, Marathi - Hirākas, Tamil - Annabedhi, Annapeti (S.F.I.), Telugu - Annabhedi, Urdu - Hira Kasees, Zaj-e-Asfar, Tutia-e-Sabz (N.F.U.M.)

Broad Classification

Hydrous ferrous sulphate

Origin and occurrence:

Kasis, a secondary mineral, results from the decomposition of pyrites in the zone of oxidation and is found in small quantities wherever pyrite occurs. It occurs widely as efflorescence on the walls and timbers of mine workings. Kasis is commonly associated with chalcanthite, gypsum and other hydrous basic sulphates. Mostly, commercially manufactured Kasis as a chemical is used for Ayurvedic formulations in the country.

Physical Properties

Nature : Massive lumps, Colour : Greenish white, Streak : White, Cleavage : None, Fracture : Uneven, Lustre : Earthy, Tenacity : Brittle, Transparency : Translucent, Hardness : 1.95 to 2, Sp. Gr. : 1.90 to 1.97, Taste : Sweetish, astringent taste

Chemical Properties:

Effect of Heat: 
  • Heated before blowpipe, Kasis becomes magnetic as felt by a horse-shoe magnet.
  • On strong heating in a crucible, Kasis looses water with evolution of SO2 gas giving pungent smell of burning sulphur.
  • Take about 5 g fine powder each of Kasis and borax. Heat the mixture in a crucible. A brown glassy fused mass results.
  • Efflorescence: Kasis is efflorescent in dry air. On exposure to moist air, the Kasis crystals rapidly oxidize and become coated with brownish yellow mass.
Reaction with barium chloride solution: White precipitate of barium sulphate appears on addition of barium chloride solution in Kasis solution, dissolved in purified water. Solubility in water: Take about 10 g accurately weighed fine (150 mesh) powder of Kasis in 250 ml beaker. Add 50 ml purified water to it. Stir the solution till Kasis powder stops dissolving. Put the beaker in the sun light till the solution gets completely dried up. Weigh the residue, if any. It should not be more than 5% of the initial weight of the sample. That is, solubility of Kasis in purified water should not be less than 95%. Assay : Kasis should contain not less than 25% Iron, not less than 15% Sulphur and not less than 45% SO4 (Appendix-3.1 & 3.3). Heavy metals and Arsenic: Kasis should not contain more than the stated limits for the following: - Arsenic = 2 ppm and Cadmium = 2 ppm (Appendix-3.2). Other elements: May contain the following within ± 20% of the stated limits:- Copper (Cu) 188 ppm when analysed by Atomic Abosrption Spectrophotometer method (Appendix-3.1.9 & 3.2.2).


Shall not be used in formulations without subjecting it to śodhana. Śodhana: [Ref: AFI-Part-I; Appendix-II, Śodhana-6]
  • Kasis : 1 Part
  • Bh¨¬ganīra (Bhrngarāja) [Pl.] : Q.S. for Bhāvanā Method: Powder Kasis, add quantity sufficient bhrngarāja svarasa and grind till complete moisture gets evaporated. Repeat the process for three times.

Properties and Actions

Rasa - Amla, Tikta, Kasāya., Guna - U¾´a, Vīrya - Usna, Vipāka - Katu, Karma - Vāta-Kaphahara, Keśya, Netrya, Rajah pravartaka, Krsnīkarana, Sankocaka, Balya, Kesya, Ranjana, Rakta vardhaka

Therapeutic Uses

kandū (itching); visa roga (disease due to poison); Mūtrakrcchra (dysuria); Aśmarī (calculus); Śvitra (Leucoderma / Vitiligo); Pitta Apasmāra (Epilepsy due to Pitta dosa); Pāndu (anaemia); Plihāvrddhi (splenomegaly); Krmi (Helminthiasis/ worm infestation); Gudabhramśa (prolapse of rectum); Visarapa (Erysepales); Netra roga (disease of eyes); Ślesma roga (disease due to kapha dosa)


60 – 250 mg

Important Formulations

Rajahpravartinī vati, Kasisadi taila, Kasisadi ghrta, Śankha drāvaka, Plihari vatikā

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