Shankha Bhasma is an Ayurvedic medicine prepared from Conch shell. It is used in Ayurvedic treatment of gastritis, abdominal pain, malabsorption syndrome etc.
Shankha Bhasma Uses: 
It is coolant, improves skin color and complexion.
It is useful in the treatment of gastritis, acidity, abdominal colic, malabsorption syndrome, dyspepsia, vomiting, nausea, acne, etc.
It is used as ingredient in the preparation of Palash Kshar – Alkali of Butea monosperma.
Growing children, adolescents and post-menopausal women need more calcium. 
It provides natural calcium and vitamin C for the development and maintenance of healthy bones, teeth and cell membrane.
It easily absorbs and compensates the calcium requirement of the body.
It relieves the body from the condition of calcium deficiency without any side effect like constipation and acid formation in stomach.
Shankh Bhasm dosage:
250 mg – 500 mg once or twice a day before or after food or as directed by Ayurvedic doctor. 
It is traditionally administered along with honey, lemon juice, Triphala kashaya etc.
Shankh types:
Dakshinavarta- its considered to be best, used in worship, acts as Tridosha hara, brings wealth
Vamavarta- available everywhere
Sankha Bhasma side effects:
Self medication with this medicine may prove to be dangerous.
Take this medicine in precise dose and for limited period of time, as advised by doctor.
Keep out of reach and sight of children. Store in a dry cool place.
Shanka Bhasma preparation, ingredients, how to make:
It is prepared from purified Conch shell. There are many different methods of preparation. Any one method can be used. Here is one such method.
Purified Shankha powder is ground with aloe vera juice or lemon juice, made into disc shaped cakes, dried, burnt in absence of air, in 800 – 900 degree celsius, allowed to self cooling. This process is repeated twice to obtain Bhasma.