With proper care, natural stone countertops can last a lifetime. Granite is extremely hard and can endure for more than a century. Marble, being softer, may last around 50 years or more but is more vulnerable to scratches and etching. Quartz, an engineered product, could theoretically last over 100 years, although extreme heat can damage its resin binders. Regular sealing (for porous stones), using trivets and cutting boards, and avoiding heavy impacts will help extend the life of any countertop.