The mason advised the application of a sealant on the natural stone product. We did a side by side comparison of the stone with and without the sealer. The verdict was definitely to go ahead and seal the stone. This is a very quick and easy maintenance step that can be done for less than $20 in supplies. Re-application is suggested, but we can wait a year or two and see how it looks. Zero skill is required, you just apply with a rag and let dry.
The sealant highlights the natural grain of the stone. We will unveil the finished stone wall in a few days once it is all cured.