Pakistan possesses inexhaustible supplies of clays of various types mainly found in Mianwali and Jhelum districts of West Pakistan and in Mymensingh, East Pakistan. The results show that most of the samples from Mianwali and D.I. Khan districts of West Pakistan and from Sylhet of East Pakistan after treatment are suitable for colourless glass. It is suggested that local sands could be used commercially for making colourless chemical glass after proper beneficiation and washing.