For all types and workmanships the rock must be substantially uniform and compact and with no weathered parts. Rocks with subdivision planes which might determine the breakup of the elements after the laying must be excluded.

The surface must be natural, like when just extracted, with cleft sides. The thickness can vary from 2 to 5 cm. A greater or smaller thickness (1-3 or 5-8) can be requested for particular employments. The cleft tiles must have parallel sides and right angles.

1 cm (more or less) is tolerated in the dimensions. Not more.

The sides have to be orthogonal to the surface or slightly acute.

The standard widths are: cm 10-15-20-25-30-35-40 and other measures on request.

The lengths can be equal to or bigger than the respective widths. Square tiles can be requested, as well as tiles with bigger size or with fixed measures.

The weight per square meter will range from 90 to 110 Kg.

Natural surface, as just extracted; the thickness can vary from 2 to 5 cm. Milled sides. Different thickness can be requested for particular employments. The milled-sided tiles must have parallel sides and right angles. The sides must be orthogonal to the surface.

The standard widths vary from 20 to 50 cm.

The lengths can be equal to or bigger than the respective widths. On request, the tiles can be either square or bigger or with fixed measures.

Semi-polished surface (60/70% of polished surface, 30/40 % of natural surface). Milled sides; the thickness can vary from 2 to 5 cm. The semi-polished tiles must have parallel sides and right angles. The sides have to be orthogonal to the surface.

The standard widths vary from 20 to 50 cm.

The lengths can be equal to or bigger than the respective widths. On request, the tiles can be either square or bigger or with fixed measures.