Bhasma in Ayurveda has been defined as a substance obtained by calcination.

Bhasma is a calcined preparation in which the gem or metal is converted into ash. Gems or metals are purified to remove impurities and treated by triturating and macerating in herbal extracts. The dough so obtained is calcinated to obtain the ashes.Ayurveda is the science made up of Veda (knowledge) and Ayush (life). An Ayurvedic system adopts a holistic approach towards health care by balancing the physical, mental and spiritual functions of the human body. Rasa–Shastra (vedic-chemistry) is one of the parts of Ayurveda, which deals with herbo-mineral/metals/non-metals preparations called Bhasmas.

Rasayana (immunomodulation and anti-aging quality) and yogavahi (ability to target drugs to the site) are characteristics of a properly made herbo-mineral/metals/non-metals preparation, which is also nontoxic, gently absorbable, adaptable and digestible in the body Bhasma or vibhooti is the sacred ash from the dhuni or fire of a yogi or avadhoota, or from the sacrificial fire or yajna, where special wood, ghee, herbs, grains and other auspicious and purifying items are offered in worship along with mantras. It is believed that bhasma destroys sins (paap), and that it links us with the divine. It is called ‘bhasma’ because it has the power to consume all evils. Any matter, broken up through the process of fire is reduced to its ‘bhasmic’ form, which is infinitely more refined and pure than the original matter, devoid as it is of all impurities niranjan. The grossness of matter obscures the subtle essence inherent within it, just as wood hides fire and milk conceals butter and cheese, but when it is burnt (or churned in the case of milk) only the pure essence remains. Similarly, the great heat of tapasya and the churning of the mind in meditation reveals the underlying subtle spirit or atman.