Stone that lasts.

The word granite comes from Latin, pointing to the coarse-grained structure of the crystalline rock. Granite is a common and very widespread type of igneous (volcanic) rock. It is usually medium to coarsely crystalline and can range from pale pink to black shades, depending on its chemical and mineral composition.

It is harder than marble and limestone, and so is better suited to paving business premises and other spaces with high foot traffic. Granite is almost always massive, solid and hard, which is why its use as a building and decorative stone is so widespread. The average density of granite is 2.75 g/cm³, varying up to 2.80 g/cm³. Granites suit indoor and outdoor paving, the cladding of staircases, counters and facades, and kitchen worktops.

Marble is a rock formed by the metamorphism of carbonate protoliths and the sedimentary rocks limestone and dolomite under raised temperature and pressure. It has a grainy structure and a homogeneous texture, is used in sculpture and building, and is easily cut, worked and polished.

In art the marble from Carrara is prized, the stone from which Michelangelo's David was carved. Here at home the best known is the Brač stone, prized the world over, although by its composition it does not belong to the marble group but to the limestone group. Marbles are among the most beautiful kinds of stone.

Limestone is a sedimentary rock made up of the mineral calcite, with small amounts of other minerals. Marbles and limestones are exceptionally decorative and refined, though sensitive. Porphyrites and quartzites are most often used for outdoor floors, steps, pool edges and cladding, while sandstones and travertines, because of their porosity, are most suited to cladding.

Strength is a rock's resistance to a force placed under pressure. With regard to the forces that can act on stone, we distinguish compressive force and bending strength, as well as resistance to fracture. A few examples of the magnitude of pressure on particular rocks:

Sandstones

500–1800 kg/cm²

Marbles

600–2000 kg/cm²

Granites

1500–2700 kg/cm²

Diorites

200–2700 kg/cm²

Basalt

2500–3500 kg/cm²

Hardness denotes a rock's resistance to wear, and depends on the hardness of the minerals and their structure. The degree of hardness is set on a scale from 1 to 10 on the Mohs scale, where higher numbers denote greater hardness. By the difference in hardness we distinguish:

1–2

Soft rocksgravel, gypsum, chalk

3–4

Semi-hard rockslimestones, dolomites, marbles

5–7

Hard rocksgranite, diorite, syenite

above 7

Very hard rocksporphyry, basalt, diabase

Wear is a very important consideration when choosing a rock for trafficked surfaces. The abrasion coefficient is determined by test grinding: a low coefficient denotes a high degree of wear, and a high coefficient a low degree of wear.

Every rock in nature contains a certain amount of moisture, and that is not harmful. A rock with a low degree of porosity holds about 1 % moisture. The property of water absorption matters above all in rocks with medium and high porosity: such materials are considerably less resistant to frost and so become less durable.

Igneous rocks (granites and porphyries) belong to the harder, more durable rocks, with a low capacity for water absorption and a low degree of wear. Sedimentary rocks (limestones, sandstones) hold many patterns from deposits and the remains of stone, shells and sand, so they look more beautiful and suit indoor cladding. Metamorphic rocks (marbles and quartzites) are recrystallised igneous and sedimentary rocks, in principle more stable than sedimentary rocks.

If you are hesitating between two or three options,get in touch or come to the showroom: samples under natural light always show what a photograph cannot.