How to choose the right natural stone based on your design

Types of natural stone:

1. Slate: metamorphic rock composed of clay and sand, 6-7 hardness (out of 10) on the Mohs scale, compact, low porosity, durable against acids and freeze-thaw cycles, versatile and hard-wearing. Slate splits naturally into thin sheets. It can can used for interior and exterior decoration projects and requires yearly treatment for surface. There is a risk of tiles chipping on the edges.

Wurtzbach Church – Germany

2. Granite: igneous rock composed of feldspar, quartz and mineral, 6-7 hardness on the Mohs scale, compact, low porosity, scratch durability and acid resistant, durable against weather conditions and hard-wearing. Granite is suitable for any type of finish and is recommended for medium and high traffic areas. It requires maintenance treatments on long term basis.

Mount Rushmore – USA

3. Limestone: sedimentary rock, composed of limestone / dolomite and skeletons fragments from marine organisms (shells deposits and fragments), medium hardness (3-4 on the Mohs scale), medium porosity. It is durable in weather conditions and homogenous in terms of granulation and color (essential for project updates). Limestone can be used for interior and exterior decoration projects and also large buildings. It is available in a wide range of shapes and sizes and requires constant aftercare. Limestone is popular for fireplace cladding projects and is perfect for flooring, especially bathrooms and showers. Limestone countertops surface must be treated, considering its sensitivity against corrosive agents and scratches. There are also very porous type of limestone, with a rustic look.

Keops Pyramid – Egypt

4. Marble: metamorphic rock composed of limestone, dolomite or serpentinite, with medium hardness (3-4 on the Mohs scale), sensitive to scratches and corrosive agents. Marble is used as bulding material for 5 000 years.

Florence Cathedral – Italy

Classic marble is actually pure calcium, without mineral interference for adding color. Thassos Marble is famous for being a white, clean marble. Pink marble obtains its color from iron oxide. Green marble and dark red marble contain serpentinite, with a high percentage of magnesium. Gray marble contains graphite and is recommended for interior decoration projects (fireplaces, countertops, bathrooms) and less for flooring and exterior cladding. It is suitable for any type of finish and requires treatment on regular basis.

5. Sandstone: sedimentary rock formed by cemented grains of sand. Having a granular structure, this natural stone is composed of quartz and feldspar. Sandstone has 6-7 hardness value on the Mohs scale and is available in a wide range. A weatherproof stone, very easy to work with, sandstone is very porous, sensitive to stains, durable against scratches, acids, water and requires constant maintenance. Sandstone is recommended for interior and exterior decoration projects, in constructions and for paving, cladding, flooring, water fountains, statues, garden landscape and as abrasive material.

Luxor – Egypt

6. Travertine: similar with limestone in terms of structure (calcium carbonate), with shallow cavities as its main feature and available in a wide range. Travertine is highlighted by an interesting and atypical finish with a wide color variation and it requires consistent treatment of the surface. Travertine is recommended for interior and exterior decoration projects, tiles can be grouted if needed and is also recommended for bathrooms sinks.

The Colloseum – Rome, Italy

An overview leads to the following comparison:

1. slate: high hardness, low porosity, wide color variation, high scratch durability and acid resistant, hard-wearing and recommended for interior and exterior decoration projects.  

2. granite: high hardness, low porosity, wide color variation, high scratch durability and acid resistant, hard-wearing and recommended for interior and exterior decoration projects.

3. limestone: medium hardness, medium porosity, color consistency, average scratch durability, low acid resistant, hard-wearing and recommended for interior and exterior decoration projects.

4. marble: medium hardness, medium porosity, wide color variation, average scratch durability, low acid resistant, hard-wearing and recommended for interior and exterior decoration projects.

5. sandstone: high hardness, high porosity, wide color variation, high scratch durability and acid resistant, hard-wearing and recommended for interior and exterior decoration projects.

6. travertine: medium hardness, medium porosity, wide color variation, average scratch durability, low acid resistant, hard-wearing and recommended for interior and exterior decoration projects.