HVAD ER DE BØDERE NATURSTEN, OG HVOR KAN DE BRUGE? landskabssten

Hvorfor er nogle natursten considered to be soft when they all appear to be hard? The answer lies within ‘relative’ hardness. Mohs scale of hardness was invented in 1812 and compares the relative hardness of ten minerals. Diamond is the hardest and rates a 10, while granite is the toughest natural stone at 6. Limestone comes in at 3 as does its metamorphic counterpart, marble. Softer stone is easier to dress or carve but does not wear or weather quite as well as harder stone. Here we discuss some of the more popular soft stones along with suitable applications.

Uregelmæssige sten

Sedimentær bjergart

Kalksten, sandsten og skifer er de mest almindelige typer af sedimentære bjergarter. Disse blev dannet gennem et enormt pres, over millioner af år, der bar ned på sediment, der var faldet til havbunden.

Skifer

The layers in slate are described as being “foliated” and they are easily split apart to create whatever thickness is required. UK slate is considered to be hard and was traditionally used as roofing, while soft slate is found in China, Spain, Italy and the USA. With a broad range of natural slate colours, a multiple array of designs can be achieved, from contemporary to classic, rustic to refined. Slate is often recommended for high traffic areas, thanks to its remarkably durable composition. It is also non-porous and does not easily react with acid liquids. It is fire proof, weather resistant and achieves good slip resistance dues to its riven finish.

Kalksten

Limestone is a very common building material and is formed mainly from the mineral calcite, derived from the calcium in bones and seashells deposited over the millennia and forced together through pressure. While it also contains magnesium, it is harder and more weather resistant, and can also be polished. Portland stone from the eponymous island in Dorset is probably the single most famous type of limestone and was used to build many of London’s great buildings. It is used for external cladding as well as paving, fireplaces and other internal and external decorative features. Its soft colours are its trademark visual attributes.

Sandsten

Sandsten var nok den mest brugte byggesten før 1800, til alt fra broer til statelige bygninger. Som det kan udledes af dets navn, er det dannet, når sand, organisk materiale, calcit og en række andre mineraler blev smeltet sammen under et utroligt pres gennem årtusinder. Fås med enten en grov eller fin tekstur og leveres traditionelt i en mat finish. Primært creme, rød eller grå i Storbritannien, dens farve afhænger af de yderligere mineraler, der er indeholdt i den. Silica giver hvidhed, mens jern giver en rødlig-brun farvetone. Dens vigtigste anvendelsesområder er vægge og gulve eller udvendig belægning.

Marmor

Marmor er et derivat af kalksten, dannet gennem metamorfosen af ​​kolossal varme og tryk over millioner af år. Selvom det er relativt blødt sammenlignet med andre sten, har marmor en tendens til at polere utrolig godt. Traditionelt bruges marmor i døre og er med til at skabe en high-end finish.