Dr Shubhabrata Mukhopadhyay (b Dec 20, 1965) of Jaipur, a geologist by profession, has made 435 masks since 2001. The sizes vary from 5 in to 4 ft in various shapes - square, round, oval to trapezium. Colours of the masks depend on the colour of the rocks and minerals used. He has used fifty-five types of rocks and minerals which include granite, marble, basalt, quartzite, amethyst, Albitite, Bismutite, Wollastonite, Zeolite etc, collected from different parts of India.