The Thar Desert in Rajasthan is subjected to significant sand migration (as high as 30 m/year) due to vigorous aeolian activity, and Rajasthan is renowned as India’s leading producer of marble, contributing over 94% to the nation’s marble production. However, the use of non-engineered processing and polishing results in the discarding of over 70% of raw marble stone as slurry powder, resulting in vast dumping ground requirement and poses environmental hazards. This study employs waste marble slurry powder (WMSP) to stabilize the desert sand in Rajasthan, using geopolymer technology. The experimental plan included the understanding on compaction characteristics, compressive strength through unconfined compressive strength (UCS) testing and microstructural analysis using X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effect of varying WMSP by dry weight (10, 20, 30, and 40%) on strength characteristics is evaluated. It can be concluded that the use of calcium carbonate-rich WMSP and desert sand in geopolymerization forms a strong CASH/NASH bond formation leading to higher compressive strengths and thereby stabilized desert sand. Overall, the current work encourages the use of WMSP as a robust and sustainable strategy to mitigate the sand dune erosion as well as efficient reuse of waste marble slurry.