Marble:

In its geological definition, “Marble” is the formation of rocks such as limestone and dolomite, which are transformed under certain temperatures and pressures, crystallize again and acquire a new structure. These are called Real Marble..
In the industrial sense, “Marble” covers all kinds of rocks that can sold, bought and get good polish when they are brightened. Regardless of the type and composition of the rock, it is sufficient for the rocks to be considered as marble, as they can be removed as blocks, cut and polished. Examples of rocks in this class are granite, syenite, travertine and onyx etc.