In this work a new microwave-heating procedure is presented as a viable alternative for both the conventional and ultraviolet (UV) curing systems used in the natural stone industry. Both thermal simulations and experimental tests demonstrate that microwave energy highly reduces curing and storing times while maintaining the product's final quality. Several polymer mixtures have been obtained from commercial products and fillers for maximum microwave absorption and their complex permittivity has been properly measured. A continuous industrial microwave oven has been built specifically for this purpose and tested on Crema-Sierra Puerta marble samples and commercial epoxy and polyester resins.