(a) Optical micrograph showing mixed Gd-Ca heptamolybdate (GdCaHM) crystal as a spherulite and a square platelet. (b) Scanning electron micrograph showing surface feature of spherulite crystals wherein number of spherulites are coalesced together with fiber like structure. (c) Scanning electron micrograph showing mixed GdCaHM crystal with cracks which results due to gold coating because of the presence of water content. (d) Scanning electron micrograph showing formation of growth layers in the growing crystal, suggesting two-dimensional nucleation and pilling up of growth layers.