This technical analysis benchmarks the chemical resistance of 100% natural quartzite and slate against the environmental degradation typical of manufactured concrete veneers. We evaluate the impact of acid rain, sulfate attack, and pigment oxidation on synthetic binders, contrasted with the chemically inert minerals and permanent UV stability of direct quarry-sourced stone. By meeting ISO 12944-9 C5-M marine standards for salinity resistance and ensuring 95% hue uniformity, Top Source Stone provides B2B stakeholders with a project-ready solution that eliminates long-term liability in high-pollution and coastal architectural environments.