Recent developments in Chemical Vapour Deposition (CVD) processing with its inherent advantages provide a feasible route for producing high quality optically transparent ceramic materials. CVD process feasibility of the reaction between Zn and H2S in obtaining optical quality ZnS deposits are evaluated with respect to the free energy requirements. Rayleigh number (R-a) of 10(6) corresponding to laminar flow indicated optimum flow velocities during CVD processing. Deposits show desirable thickness uniformity of 0.55% per cm and were found to have a phase pure ZnS XRD phase. EBSD patterns exhibited a highly oriented columnar ZnS grains and the specimens have shown the theoretical transmission values in the IR ranges.