How to get rid of grease and oil stains?
The grease and oil spots (including the ones of mineral derivation) are removed by applying a "paste" made of a absorbent powder (gypsum, talc, sepiolite, etc.. ).
The sepiolite acts much better, thanks to its wide surface, containing a suitable solvent such as: trichloroethylene, heptane, toluene, hydrocarbons and some mixtures.

Spread on an area which is twice the stain, a layer, thick at least 1 cm. Wet it with the solvent, in order to make it taking the consistency of a paste and slowly let evaporate the solvent.
Remove the paste when it becomes dry, repeating the application if traces of the stain still remain.
Sometimes, when the stain is penetrated deeper or when the temperature is too high (eg. in the summer) it is necessary to slow down the evaporation of the solvent, using solvents not easily evaporable (eg. hydrocarbons, toluene, etc. .) or covering the paste with a glass, a cup, etc.. overturned.

Be careful because the solvent is often flammable and its vapours harmful: operate away from flames and ventilate properly if the application is made in enclosed spaces.
Note that if the stain is made of only cooking oil, good results are obtained also using a solution of ammonia, instead of hydrocarbonic solvent.

How to remove cigarettes “burnings” from table and slabs?
They can hardly been removed, especially if is a marble slab.
Anyway, try to apply repeatedly a mixture made of sepiolite and toluene, which has to cover completely the spots. Leave it for some hours and repeat the application.
Be careful not to breathe solvent vapours and do not work next to flames.
When the matter” is pretty hard, apply also hydrogen peroxide.

How to protect floorings from spots?
For common spots (the so called water-soluble spots) treat the surface with specific water-repellent products, better if silicone ones. If you have to protect the surface from oily spots (kitchen and dining room floorings, tables, etc..) treat them with specific oil-repellent products such us waxs, fluorinated polymers and make a periodical maintenance.

I am working on a contour CNC, do you have tools, able to write and make grooves on marble and granite?
OMA SYSTEM realized a wide range of tools for CNC machineries, able to execute many profiles, both on marble and on granite, but we do not have cutters to carve.
We are able to realize them “ad hoc”. If you can send us the features of the mills needed, we will let you know if we can satisfy your request.

How can I understand if a granite can make spots and rusty dots?
Just treat a piece of marble slap with the hydrogen peroxide, letting it for few hours. If spots and rusty zones will appear, the granite will probably react in the same way (slowlier), when exposed to atmospheric agents.

Which is the minimum thickness to cut a stone?
Thanks to the current technologies, the thickness can be of 4 mm., but the material can loose its resistance and has to be stiffened with mountings, the most well-known is “aluminium honeycomb”.

How to protect the marble from the risk of spots in your kitchen?
We suggest you not to use products which make a film, since they make easily change the colour of the material.
The material polishing has not just an ornamental function (to exalt its colour and the marble vening) but also a mechanical one as, stopping the material pores, it makes it waterproof.
A more traditional system suggests, for surface finishing, the dressing (which doesn’t stop the pores), it has to be made sprinkleing the surface with olive oil, that seeping deeply into the free interstices, makes the marble inert to liquids seeping, due to the oil waterproofness.

Which is the difference between marble and granite?
Marble has a calcareous origins (it is made of calcium carbonate), it has a not-high hardness, reacts often to acid, also to faint ones (vinegar, lemon juice) and it can be easily polished and workable. Granite has a siliceous origins (it is made of a complex mixture of silica and silicate), it has a greater hardness, doesn’t react to any kind of acids, it can be hardly polished, has a granular and dense frame and can have various colourings, depending on the pigment agents in it. The chemical-physical-mechanical features of granites are very different from the marble ones and that’s the reason why their appliance fields have to be chosen carefully. Generally, marbles are usually used for interiors, while granites also for exteriors.

Why coloured marbles can fade when are kept outside?
The colour is due to the presence and to the concentration degree of some pigments inside the minerals which compose the materials rocky mass; the colour of these pigments is altered by atmoshperic agents action they interact with (water and content substance, solar irradiation, temperature range, etc...)