+0
I've translated a text regarding a stone. I paste four paragraphs  that may be somewhat problematic. Could you point out if there any awkward passages or unclear expressions?

Thanks to its almost continuous outcrop area along the foothills, Sarnico sandstone is to be found practically everywhere in classical architecture and art, but also in agriculture and general civilian uses for technical and practical purposes.

Its excellent workability and the presence of sizeable outcropping seams that make possible either large realisations or aesthetically significant street façades, are at the basis of its widespread use.

It is suitable for masonry and wall lining when cut in square slabs. It is sensitive to stagnant water and frost and subject to wear and tear, which can become manifest in the form of surface disintegration and pulverisation.

The material is extracted in an open-air site with the use of diamond wire: the opening phases involve digging a trench which isolates a mass of stone. The ledge is subsequently divided by drilling a series of coplanar holes loaded with explosive for blasting.
+1
Thanks to its almost continuous outcrop area along the foothills, Sarnico sandstone is to be found practically everywhere in classical architecture and art, but also in agriculture and general civilian uses for technical and practical purposes.

The connection between the extent of the outcrop and its wide use is not clear enough. The reader gets as far as "everywhere" still thinking you are talking about its occurrence in nature ("is to be found"). I do not believe that the sandstone is found practically everywhere in art. You want to contrast its use in art with its other uses, but the contrast as you have it is not strong enough for a "but".

Its excellent workability and the presence of sizeable outcropping seams that make possible either large realisations or aesthetically significant street façades, are at the basis of its widespread use.

"Sizeable" is faint praise. The subject of the sentence is too long, and no comma is called for. "Facade" is an English word and uses the English alphabet, which has no cedillas in it. "At the basis of" is not English—you mean "the basis of".

It is suitable for masonry and wall lining when cut in square slabs. It is sensitive to stagnant water and frost and subject to wear and tear, which can become manifest in the form of surface disintegration and pulverisation.

"Cut into square slabs" is better. It is not subject to wear and tear, it is subject to damage caused by wear and tear.

The material is extracted in an open-air site with the use of diamond wire: the opening phases involve digging a trench which isolates a mass of stone. The ledge is subsequently divided by drilling a series of coplanar holes loaded with explosive for blasting.

How is diamond wire used? The colon leads nowhere. What ledge? "Parallel" is a much more familiar word than "coplanar". If you are going to describe the quarrying procedure, describe it from start to finish.
Comments  
Teachers: We supply a list of EFL job vacancies
enoonI do not believe that the sandstone is found practically everywhere in art. You want to contrast its use in art with its other uses, but the contrast as you have it is not strong enough for a "but".
I'm going for "not only - but also". I'll also replace "practically everywhere" with "frequently".

Thanks to its almost continuous outcrop area along the foothills, it is frequently found not only in classical architecture and art, but also in agriculture and general civilian uses for technical and practical purposes.
"Sizeable" is faint praise. The subject of the sentence is too long, and no comma is called for. "At the basis of" is not English—you mean "the basis of".
I'll try with "extensive" rather than "sizeable". I'll also reverse the order of the sentence to leave the long subject at its end.

The basis of its widespread use are its excellent workability and the presence of bulky outcropping seams that make possible either large realisations or aesthetically significant street facades.
What ledge?
I'll specify by saying "rock ledge".

Thanks again for your useful observations.
Your revisions are good.