Naga Bhasma (calx of Naga i.e. Lead), an unique mineral product used traditionally in the management of Prameha (Diabetes) and Netra Vikaras (Eye disorders) was prepared according to the prescription in the Ayurvedic classics and subjected to various bhasma pariksha (tests for calx), including the Namburi Phased Spot Test (NPST), one of the qualitative tests described for various Ayurvedic preparations. NPST helps to differentiate between, and thus identify, various hasmas (calx). It depends upon the pattern of the spot, which develops after a specific chemical reaction. Naga bhasma prepared by classical reference in our department along with three market samples were subjected to above said tests and the results were compared. The various bhasmas exhibited marked differences in color, and though NPST yielded desired results for all the samples, there were difference in their spot pattern and color. The bhasma prepared in our department had produced the nearest results to standard NPST of Naga Bhasma. 

Keywords: amburi Phased Spot Test (NPST); Naga Bhasma.