Properties of natural stones
 The choice and application of natural stones depend on their various properties, but also and from their cost.
It depends on how it is frequent these stones meet in the nature, from their properties and from their art qualities.
 Durability depends on mix density. Natural stones have often the big density and consequently approach for parts of the buildings bearing the big compressive load. Besides, stones have the big weight.
Their hardness can be evaluated by means of a Mohr’s’ scale.
  Stability against aeration depends on a stone porousness.
The porous stones, as for example certain sandstones, have the big ability of a absorbing in of a moisture, hygroscopicity.
The frost and aeration can destroy them. At misplacement in a wall of such stones the condensate can be formed.
It also guides to building damages.
 Dioxide of carbon СО2 and dioxide are gray SO2 during a rain can to be dissolved and form acids which destroy a natural stone. Change of temperatures can lead to a clinking. Molds, lichens, a grass and roots of trees sprout on wet stones in the smallest cracks and damage them.
 The stone machinability depends on density and hardness.
Some sorts of natural stones can be sawn easily in a wet condition (travertine). Especially firm stones, for example, basalt or granite, require the big expenses for their processing.
They can be processed tools with the big breaks in job. Owing to their dense structure it is possible to polish firm natural stones.
The smooth surface turns to shine.
 The stone surfaces have various structures. Color, texture and appearance can be very diverse.
Filed under: Building Stones