Pietra Cardosa is a stone mined in Italy. A similar stone with the same name is also quarried in New England.
Both look like slate but don't have the strength and moisture-repelling properties inherent in slate. Pietra cardosa is controversial in that what type of stone it is has yet to be determined, which results in questions as to its longevity and care.
The stone is rough-hewn and has shown to be resistant to most stains. A pietra cardosa countertop requires little care and maintenance and will last as long as granite and marble.
Sealing the Countertop
The matte-black look of a pietra cardosa countertop is enhanced after sealing, which should be done within a month after installation. This is accomplished in two steps using a commercial product, preferably purchased from a stone dealer rather than a grocery store because of the different ingredients found in sealants.
Rub the liquid sealant in, let it sit according to directions and wipe it dry. The color of the stone will become slightly shinier, but the look of the matte finish will still be evident.
Protecting the Stone
Water rings, juice stains, wine and acid affect stone in different ways. Unlike Formica, stone is a natural product and can be porous, depending on the specific piece of stone.
The black pietra cardosa shows marks more readily than a lighter stone, so wipe the countertop immediately after every use even if it has already been sealed.
Durability of Pietra Cardosa
Stone is noted for its durability. A hot pan can be taken from the stovetop and placed directly onto the countertop.
While the risk of marring the stone is minimal, use a small piece of the pietra cardosa placed on top of the counter as a trivet instead of using the counter directly.
If the pietra cardosa does become scratched, lightly scrub the counter top with steel wool to remove the scratch. Since the top is stone, the color will continue through the piece.
Use the sealant to protect the scarred area and to bring the finish up to the look of the rest of the counter.