At first glance, marble and granite may look like the same stone. We use them in building structures and furniture, and they both come in appealing colors.
However, these natural stones do have their differences; this is the question that this article aims to answer.
Natural marble and granite are durable stones that have their own elegance. While it may be challenging to see, we can find their main differences in their:
- composition
- weight
- hardness
- porousness
- physical appearance
- cost
How to Identify Between Marble and Granite
To identify which natural stone is marble or granite, we must know their traits. This way, we can differentiate them better since we know what to look for.
Origin and Composition
Since both are natural stones, then they are created from the natural geological process of the earth. Although, they will vary in composition.
Marble
Have you encountered people referring to marble as limestone and vice versa? While we cannot interchange them, marble was limestone or dolomite before it changed form.
Metamorphism is when the limestone or dolomite is exposed to extreme heat and pressure. This also alters the mineral composition of the two stones and results in marble creation.
Marble is composed mainly of calcite, a polymorph of calcium carbonate (CaCO3). The other minerals are listed below:
- quartz
- clay minerals
- iron oxides
- graphite
- micas
- pyrite
These minerals also affect the colors and patterns of natural marble.
Granite
Granite is from the igneous rock family, created from the slow crystallization or cooling of magma below the surface of the Earth; the place is specifically the magma chambers or plutons. With this said, we can generally locate granite in mountainous areas.
This stone’s composition is mostly quartz and feldspar (potassium feldspar and sodium feldspar). Granite’s other minerals include the following:
- mica
- amphibole
- silica
- alumina
- potassium oxide
- soda
- lime
- iron
- magnesia
- titania
The same with marble, granite’s minerals determine its colors and patterns.
Hardness and Heaviness
The two stones are known to be heavy and hard, which also correlates to their durability. In construction, the following measurements of resistance are required as follows:
- Compressive Strength – no specific numbers are given, but in construction, we require concrete walls to have at least 3,000 to 5,000 psi.
- Tensile Strength – no exact numbers are specified, but a standard concrete can be 700 psi and above.
Marble
In the Mohs Scale of Hardness, marble has a grade of four (4). While marble is hard, it is also very malleable so we often use it for sculptures and molding projects. This is evident in the number of statues built earlier, like David by Michelangelo.
In civil engineering, marble has a compressive strength of up to 20,000 psi. This refers to the stone’s resistance to compression or how much load it can tolerate.
Depending on the type of marble, it has a tensile strength of 7.00 to 20.0 MPa (1,015.26 to 2,900.75 psi). This is the material’s resistance to a pulling force or tension before breaking into two.
Lastly, the weight. Marble is significantly heavier than granite, with a measurement of 6.67 pounds per square foot, despite being softer than the latter.
Granite
Granite is harder than marble, with a grade of 6.5 on the Mohs Scale of Hardness. With this hardness, can we still sculpt granite? The answer is yes. It doesn’t bruise, which allows us to perform more aggressive carving techniques.
In terms of resistance, granite has a compressive strength of 19,000 psi and a tensile strength of 4.8 MPa (700 psi).
Granite is heavy but lighter than marble. It is 6.5 pounds per square foot, 0.17 pounds less than marble.
Porousness
Porosity is the vacant or empty space in a stone; it is the ability of the marble or granite to hold fluids or compressed air.
Marble
Marble is more porous than granite. We recommend regular sealing, especially for furniture exposed to liquids like a countertop or a table. We also don’t advise marble in places with high precipitation levels (for outdoors).
However, this doesn’t mean that marble will be immediately damaged when it comes in contact with water, for example. No stain or etch mark will occur when we immediately wipe off liquid spills—especially acids.
Plus, with proper maintenance, it will double its durability and can last for centuries, according to the National Association of Home Builders’ study of the life expectancy of home components.
Granite
Since it’s also a natural stone, granite is porous but less porous than marble. It is, therefore, more liquid and stain resistant than marble, but this doesn’t signify being more durable since both stones are sturdy.
We can use indoor and outdoor granite as it is less prone to staining, etching, and fading (under UV light) as well. Like marble, this stone can last for centuries as stated by the National Association of Home Builders.
Heat Resistance
Both stones form because of the Earth’s natural geological processes. Hence they are highly heat resistant compared with other building materials.
Marble
Marble can handle heat up to 200 degrees Celsius or 329 degrees Fahrenheit. This is why marble countertops and tables are popular, but we do not recommend directly placing a freshly-heated pan on top.
When the heat exposure exceeds the “maximum” temperature, the marble won’t break but might develop burn marks.
Granite
Granite can handle temperatures up to 249 degrees Celsius or 480 degrees Fahrenheit. Like marble, we also use this stone a lot in the kitchen. However, we advise taking precautions, such as using trays, saucers, or trivets, when the kitchen utensils are very hot.
Scratch and Crack Resistance
Marble and granite do not easily get scratched, especially when we take care of them by using stone-friendly cleaners and mild cleaning tools.
It’s not true that marble gets cracks more easily than granite. Both are hard and durable, but they also need proper maintenance. These stones can last more than 100 years and last less if neglected.
Appearance: Color and Pattern
This is where most of you get confused because some of the marble and granite colors look similar. But in this section, we will learn about their differences and how to distinguish one from another.
Marble
We can describe the colors of marble as rich and translucent because this stone is naturally shiny. In manufacturing laminated stone panels, we often pair a marble sheet with a glass backing for the floors. The result? Translucent flooring when hit by light.
The patterns are veins that also come in different colors, complementing the background.
Granite
Granite’s colors are more pigmented but are equally beautiful to marble’s. They are matte as well. Hence they cannot give a translucent effect as they do not have a naturally polished look.
However, granite’s colors give an earthy appearance that we can use as a building material or decoration.
Its patterns also have different colors that jive with the background color, and they come in speckles or patches instead of veins.
Cost
The price of marble and granite will depend on the quarry expenses—such as the labor and the quarry owner’s rate—and the market demands.
There are instances when marble will be more expensive or equal to the price of granite. This is because quality also plays a role in pricing. That’s why we have luxury and cheap stone.
Conclusion
Natural marble and granite are durable stones in our different building, furniture, and fixture projects. While they are both superior materials that are sometimes mistaken for the same, they have unique traits and differences. The article “How to Choose the Best Marble Flooring?” may help you while choosing natural stone products.
Marble is heavier, more porous, and has veins and translucence in appearance. Granite is more complex and its colors are more pigmented and matte. In terms of similarities, the two are heat, scratch, and crack-resistant and rich in minerals.
