As an Argentinian Cambrian clay slate, San Luis Phyllit is a robust natural stone material with a moderate water absorption (typically 0.3-0.8 %) and a Mohs hardness of 3-5. Wine, lemon juice, vinegar, cola, sanitary cleaners or descalers normally leave no etch marks as they do on marble or limestone — clay slates are acid-resistant in the normal range. The Mohs hardness is, however, markedly lower than with hard rocks, which makes the stone more prone to scratching.
For all applications an impregnation on a silane or polysiloxane basis is advisable. For interior applications refresh every 2-3 years, for exterior applications annually. Impregnation protects against the deep penetration of oil, grease and pigments — on the dark ground mass such discolourations are barely visible, which makes the stone a very forgiving choice for heavily used surfaces.
Day-to-day care is carried out with a pH-neutral natural stone cleaner and a soft cloth or microfibre mop. Clean warm water is usually enough. Acidic cleaners are in principle unproblematic in the normal range, but should nevertheless not be used. On textured surfaces such as riven or split, dirt can hold in the open microstructure — here occasional cleaning with a soft brush and a mildly dosed stone care product is advisable.
For kitchen worktops San Luis Phyllit is not to be recommended. The lower hardness (Mohs hardness 3-5, markedly more prone to scratching than hard rocks) and the layered mineral orientation make the material unsuitable for intensive cooking applications. For carefree black kitchen worktops we recommend a classic black granite or gabbro such as Aracruz Black, Nero Assoluto Zimbabwe, Black Pearl or Star Galaxy.
The surface finishes available from stock are listed in the »Finishes« block further down.
For exterior applications San Luis Phyllit is, with its dense slate structure, frost-resistant and weather-stable over the long term — well suited to exterior façades, pool areas and exterior terraces. The surface finishes available from stock are listed in the »Finishes« block further down. In areas with frequent salt contact we recommend an additional annual refreshing of the impregnation.
