Limestone

Limestones are a very abundant stone category and are available in a great variety of colours and densities to suite a range of uses.

The stones are formed as the remains of an ocean floor or seabed, where shells and plankton have settled and re-formed or calcified into stone. The colours are formed through the prevalence of either plant form or other oxides that have seeped into the material from above or below.
The density is due to compression which can be the result of either the weight of material above or land movement from below or either side. This kind of pressure can result in the stone crystallizing and turning into marble, but before we would classify it as marble there is a range of very dense and super durable materials we call “Hard Stone”. This is not a technical term, although stats are available to show their attributes to engineers and specifiers, but rather one that we use within the stone industry to classify stones that are verging on marble and can take a polish.

Within this hard stone category there are a range of French Stones which are well known. In the UK we know Purbeck and all around the world each country has many more to offer.

Why then use a porous or softer stone ? There are several reasons. As a cladding or building material their attributes may be good for compression and frost resistance despite their porosity and they are easier to cut and shape. Or it may be as is the case of Portland Stone that it has a matt finish which is to be desired and or it has been used for centuries in local heritage buildings.

The cleaner “White” stones also fall into this category and there are several of them ranging in amounts of speckle and shell and also density. Knowledge of these stones and experience of using them is essential so as not to be fooled into buying a cheaper substitute material that is unsuitable for the project.

We have given some indication of available sizes but depending on the size of your project these sizes are flexible and some just plain wrong so please enquire rather than assume