Mica is the name given to a group of silicate minerals that have silicon and oxygen as their 2 major components. 4 varieties of Mica or talc are described by Sanskrit writers, namely, white, red, yellow and black. Of these the white variety is used as a substitute for glass in making lanterns etc., and the black variety called Vajrabhra is used in medicine. It is of a black colour, hard and heavy, and generally known by the name of Krishnabhra or Sheabhra.

Processing of Mica
Mica or Talc is purified in the following manner. It is first heated and washed in milk. The plates are then separated and soaked in the juice of Amaranthus polygamus (tandulia) and Kanjika for 8 days. Talc thus purified is reduced to powder by being rubbed with paddy within a thick piece of cloth, when the powdered talc passes through the pores of the cloth in fine particles and is collected for use.

Talc, thus reduced to powder, is called Dhanyabhraka. It is prepared for medicinal use by being mixed with cow"s urine and exposed to a high degree of heat within a closed crucible, repeatedly for a 100 times.

Benefits of Mica
Prepared mica is a powder of brick-dust colour and a saline, earthy taste. Chemically it consists of silicate of magnesia with iron in excess. It is considered tonic and aphrodisiac and is used in combination with iron in anaemia, jaundice, chronic diarrhoea and dysentery, chronic fever, enlarged spleen, urinary diseases, impotence, etc. Its efficacy is said to be increased by combination with iron.

Dose of Mica in Medicine
In phthisis and chronic bronchitis the following called Sringarabhra is used. Take prepared talc 16 tolas, camphor, cardamoms, nutmegs, mace, cloves, root of Pavonia odorata (bala), Pothos officinalis (Gajapipul), leaves culled tejpatra, Jatamansi root, leaves of Pinus Webbiana (talisa patra), cinnamon, flowers of Mesua farrea (nagakesara), root of Aplotaxis auriculata (kushtha), flowers of Woodfordia Floribunda (Dhataki) and purified sulphur, each 1 tola, mercury half a tola. Powder the ingredients, mix and make into 4 grain pills with water. One pill at a time is to be chewed with betel leaves and ginger, and a little water is to be taken afterwards. The pills may be taken 3 or 4 times daily.

Jvarasani Rasa: Take mercury, sulphur, rock salt, aconite and copper, one part each, prepared iron and talc, 5 parts each, rub together with the juice of Vitex Negundo leaves, then add one part of black pepper and make into 2 grain pills. They are administered with the juice of betel leaves in chronic fever and enlarged spleen.

Agnikumara Rasa: Take mercury, sulphur, borax, iron, aconite, ginger, long pepper, black pepper, ajwain and opium each one part, prepared talc 10 parts, rub together for 3 hours with the decoction of Plumbago rosea (Rakta Chitraka) and make into pills of the size of black peppers. This preparation is used in chronic diarrhoea and indigestion.

Sulachanamritabhra: Take prepared talc 8 tolas, rub it with 8 tolas each of the fresh juice or decoction of the following drugs, namely, pulp of Ziziphus Jujuba (kola), Chavica officinarum (chavika), root of Andropogon muricatus (usira), pomegranate fruit, lemon juice, emblic myrobalan and Oxlais corniculata (amlalonika), and make into pills about 6 grains each. This medicine is used in loss of appetite, disinclination for food, dyspepsia, vomiting, urinary diseases, anasarca and debility.

Arjunabhra: In heart disease, mica is used with the juice of the Arjuna bark which is considered a specific for this complaint. Arjunabhra is prepared by soaking some prepared talc in the juice of the bark of Terminalia Arjuna, 7 times and dividing the mass into 2 grain pills.

Mohalakshmi Bilasarasa: This preparation is used as an alterative tonic and aphrodisiac in general debility, impotence etc. To prepare it, take mica 8 tolas, mercury 4 tolas, sulphur 4 tolas, tin 2 tolas, silver 1 tola, orpiment 1 tola, copper half a tola, gold half a tola, camphor, nutmegs and mace, each 4 tolas, seeds of Argyreia speciosa (bridhadaraka) and of datura, 2 tolas each. Mix together, rub with the juice of betel leaves and make into pills of about 6 grains each.

Galitakushthari Rasa: Take mercury, sulphur, prepared copper and iron, bdellium, plumbago root, silajatu, nux vomica, and the three myrobalans, each 1 part, prepared mica and the seeds of Pongamia glabra (Karanja) 4 parts each, rub together with honey and ghee, and preserve in an earthen pot smeared with ghee. Dose will be about a drachm. It is given in leprosy with ulceration of the toes and fingers.