Abstract

The preparation of metal- and mineral-based medicines is a distinctive part of Rasashastra. Raw materials are not considered equivalent to the finished Bhasma. They undergo procedures such as Shodhana, Bhavana and Marana, which may include heating, quenching, grinding, treatment with liquid media and repeated calcination. This narrative review examines the changes produced by these processes using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Studies of Tamra Bhasma, Lauha Bhasma, Swarna Makshika Bhasma, Naga Bhasma, Abhraka Bhasma and Swarna Bhasma show the formation of new crystalline phases, altered oxidation states, smaller crystallites and clear changes in surface morphology. The evidence also shows that crystallite size, primary particle size and agglomerate size are different measurements and should not be used interchangeably. Modern analytical methods can strengthen identity testing and batch standardization, but they do not replace classical Bhasma Pariksha. Physicochemical transformation or a nanoscale structure alone does not prove clinical efficacy or safety. More reliable conclusions will require stage-wise sampling, complete heating records, validated analytical methods, toxicological assessment and appropriately designed clinical studies.