Strength and By-products of coal combustion process in thermal power plants and stone crushers are usually left unutilized and as such degrade the environment. India produces more than 200 million tonnes of coal fly ash annually, most of which is left untapped. The goal of research is to create durable, cheap building blocks from these environment sustainable waste by-products. Pond ash and fly ash were procured from the NALCO’s Captive Power Plant in Odisha, India and stone dust from a crusher facility on the outskirts of its capital city. Four trial mixes were prepared, with pond ash levels ranging from 10 to 40%. Scanning electron microscopy and X-ray diffraction were done on the ash samples and on the trial mix having best outcomes. Compressive strength tests were conducted in 24 cubes on day 7 and 28 after ambient curing. The trial mix that contained 60% fly ash, 10% pond ash and 30% quarry dust as the parent mix tested to have a 28-day compressive strength of 7.94 N/mm2 and water absorption of 15.96%. Presence of pozzolana and finer fly ash particles increased its reactivity and resulted in higher strength of blocks. The results may support production of bricks, pavements, and cement mortar that would share the energy demand of expanding population.