How does granite compare to marble for outdoor sofa durability in coastal areas?

When choosing natural stone for outdoor sofas in coastal areas, durability against salt, moisture, and weather is crucial. Granite outperforms marble in coastal environments due to its superior hardness (6-7 on Mohs scale vs marble's 3-5) and lower porosity. Granite's quartz content makes it highly resistant to salt corrosion and etching, while marble's calcium carbonate composition is vulnerable to pitting and staining from salt spray.

Both stones require sealing, but granite maintains its integrity longer between treatments. Marble may develop a weathered patina over time, which some designers appreciate, but granite retains its polished appearance with minimal maintenance. For high-traffic coastal outdoor furniture, granite's impact resistance and thermal stability make it the more practical choice, though marble offers unmatched elegance for protected areas.

Consider granite for primary seating surfaces and marble for accent pieces if aesthetics outweigh durability concerns. Proper installation with drainage and regular cleaning will maximize either stone's lifespan in coastal conditions.