Gallium-sodalite (Ga-SOD) was synthesized from a half cup-type sodalite cage layered silicate (named; HLS: [(CH3)(4)-N](2)Na-2 [Si10O20(OH)(4)] 5.6H(2)O) by solid-state transformation. HLS was easily converted to the Ga-SOD by mixing it with Ga(OH)(3) and heating at 150 degrees C for 3 h after adding a small amount of H2O as the solvent. Ga was inserted into the T-site of the SOD cage obtained.