Differences between Granite and Marble

Granite vs. Marble

Granite and marble are natural stones used in construction and decoration. Though often used for similar purposes, such as countertops and flooring, they have distinct geological origins which result in different physical properties and performance characteristics. Granite is an intrusive igneous rock, whereas marble is a metamorphic rock.

Comparison table

Category	Granite	Marble
Rock Type	Igneous	Metamorphic
Formation	Formed from the slow cooling of silica-rich magma deep within the Earth's crust.	Formed from limestone or dolomite rock subjected to intense heat and pressure, causing the original carbonate minerals to recrystallize.
Composition	Primarily composed of quartz and feldspar, with smaller amounts of mica and amphibole minerals.	Primarily composed of recrystallized carbonate minerals, most commonly calcite or dolomite.
Appearance	Typically has a granular, flecked appearance with interlocking crystals of different minerals.	Characterized by veining or swirls, which result from mineral impurities in the original limestone.
Hardness (Mohs scale)	6–7. It is resistant to scratching from common kitchen utensils.	3–4. It is softer and can be scratched by metal blades and other harder materials.
Porosity	Porous, but generally less porous than marble. Sealing is recommended to prevent staining.	More porous than granite, making it more susceptible to staining if not sealed.
Reaction to Acid	Generally resistant to acids found in common household foods and cleaners.	Highly reactive to acids such as vinegar or citrus juice, which can cause etching, a dulling of the polished surface.
Common Uses	Kitchen countertops, high-traffic flooring, paving stones, exterior cladding, monuments.	Bathroom vanities, flooring, wall tiles, fireplace surrounds, sculptures, and architectural details.

Venn diagram comparing Differences between Granite and Marble

Durability and maintenance

The differences in hardness and composition between granite and marble directly affect their durability and maintenance requirements. Granite's hardness, rated between 6 and 7 on the Mohs scale, makes it highly resistant to scratches and heat. This durability makes it a common choice for kitchen countertops, where it can withstand direct contact with knives and hot pans.

Marble is significantly softer, with a Mohs hardness of 3 to 4. This makes it more prone to scratching and chipping from everyday use, particularly in a busy kitchen environment.

Both stones are porous and can absorb liquids, leading to stains. Marble is generally more porous than granite and requires regular sealing to protect its surface. The primary component of marble, calcium carbonate, is chemically reactive with acids. Spills from acidic substances like lemon juice, vinegar, or wine can cause a chemical reaction that etches the surface, leaving a dull spot. Granite, being composed mainly of silicate minerals, is more resistant to acid etching.

For maintenance, both stones should be cleaned with pH-neutral cleaners. Due to its vulnerability to etching, marble requires more careful attention to prevent contact with acidic substances.