HVA ER DE MYKERE NATURSTENENE OG HVOR KAN DE BRUKES? landskapsstein

Hvorfor er noen natursteiner 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.

Uregelmessige steiner

Sedimentær bergart

Kalkstein, sandstein og skifer er de vanligste sedimentære bergartene. Disse ble dannet gjennom et enormt trykk, over millioner av år, som bar ned på sediment som hadde falt til havbunnen.

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.

Kalkstein

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.

Sandstein

Sandstein var trolig den mest brukte bygningssteinen før 1800, for alt fra broer til staselige bygninger. Som det kan utledes av navnet, er det dannet når sand, organisk materiale, kalsitt og en rekke andre mineraler ble smeltet sammen under et utrolig trykk gjennom årtusener. Tilgjengelig med enten grov eller fin tekstur og leveres tradisjonelt i en matt finish. Primært krem, rød eller grå i Storbritannia, fargen avhenger av de ekstra mineralene som finnes i den. Silica gir hvithet, mens jern gir en rødbrun fargetone. De viktigste bruksområdene er vegger og gulv, eller utvendig belegning.

Marmor

Marmor er et derivat av kalkstein, dannet gjennom metamorfosen av kolossal varme og trykk over millioner av år. Selv om det er relativt mykt sammenlignet med andre steiner, har marmor en tendens til å polere utrolig godt. Tradisjonelt brukes marmor i dører og bidrar til å skape en high-end finish.