Limestone from WK Marble and Granite

Limestone rocks are sedimentary rocks that are made from the mineral calcite which came from the beds of evaporated seas and lakes and from sea animal shells. Limestones are calcareous rocks made up of at least 50% of carbonate mostly in the form of calcite, aragonite, and dolomite. Limestones are regarded as non-clastic sedimentary rocks that can be formed from many geological processes. They are texturally, structurally and mineralogically extremely diverse - characteristics which reflect their derivation, environment of deposition, and post depositional history. A large proportion of limestones are biogenic (contain fossil material), but there are also chemically deposited limestones which are important as building stone, namely travertine.

Limestone fizzes in vinegar, which means that it reacts to acids. Wine, carbonated drinks, fruits and fruit juices, vinegar, and even some natural waters will react with these carbonate rocks.

Another characteristic of limestone is their softness relative to other rocks such as granites. The softness is mainly due to the mineral composition. Calcite generally has a hardness of 3 on the Mohs scale of hardness whereas dolomite and aragonite are slightly harder (3.5 to 4). Limestone can be easily scratched by most common implements in the house such as cutlery, coins, tools, keys, toys, etc., so one should never expect that nicely polished or honed limestone surfaces are going to stay that way for ever.

A typical physical characteristic of limestone is its intrinsic porosity. Many limestones, particularly the biogenic ones, have a medium to high degree of porosity. Porosities of 10-30% are common in the French limestones.

One important inherent structural aspect in most limestones is the presence of very fine, squiggly brownish called stylolites, formed during the compaction and lithification of limestones. The brownish colour is due to the presence of hydrated iron oxide but concentrations of clays and/or sulphides can also be present. These stylolites are natural planes of weakness and can transmit fluids, these fluids can react with any expanding clays and can physically weaken the limestone.

In the natural stone trade, it is generally accepted that any limestone that can be polished can also be called a marble. If a limestone has undergone some post-depositional changes then some recrystallization of minerals will have occurred. These crystals might still be quite small but will accept good polish. Indeed, it is this group that appears to be capturing a significant portion of the stone market particularly some of the limestones from Oman and Saudi Arabia and the beige-coloured Jurastone from Germany are used for the external cladding due to their ability to accept polish.

Limestone has a broad range of color from gray/buff to cream/tan to bone white. Limestones can be polished, honed, sand blasted or bush hammered depending up on the application it is to be used.

WK Marble & Granite imports 20mm and 30mm random slabs in polished and honed forms and tiles in various dimensions and thickness.