 In the 13th century the town of Kashan in Iran was an important centre for the production of fritware.Abū'l-Qāsim, who came from a family of tilemakers in the city, wrote a treatise on precious stones in 1301 that included a chapter on the manufacture of fritware.His recipe specified a fritware body containing a mixture of 10 parts silica to 1 part glass frit and 1 part clay.