Wipe away wet nail polish as soon as possible with a paper towel.
Moisten a cotton pad with nail polish remover; nonacetone is more gentle, but Silestone can tolerate acetone-based products. Rub the area lightly to remove any remaining nail polish residue.
Wipe the area with a damp sponge to remove the nail polish remover from the surface. Dry the Silestone with a paper towel.
Scrape off hardened nail polish on Silestone with a single-edged razor blade or utility scraper. If the polish won't loosen, dab it with a cotton swab moistened with nail polish remover. When the polish starts to soften, scrape it again.
Wipe the area with a nail polish remover-moistened cotton pad to remove any nail polish residue.
Rinse the spot with a wet sponge, then dry with a paper towel.