To remove everyday stains on granite bowls, the surface should be cleaned with a solution of a mild dishwashing detergent and water; then dried with a soft cloth or sponge. More stubborn stains can be removed by using a mild abrasive cleaner such as Ajax®.
If a tough stain has become ingrained in the bowl, mix a solution of one part bleach in forty parts water and let stand in the sink overnight. Drain and rinse thoroughly. This process is only for extreme circumstances and should not be used regularly.
Mineral deposits can be removed by using a weak solution of vinegar and water. Rinse thoroughly and dry.
Do not store heavy or sharp objects above a granite sink. If they fall, or make contact with the sink, the granite can chip or scratch. A chipped or cracked granite sink can be very difficult and costly to repair or replace.
Since marble and onyx are porous stones, they are more susceptible to staining and damage than other materials. Therefore, non-abrasive cleansers which do not contain acid are required for cleaning.
To remove soap scum, use a mild liquid detergent and a soft sponge or cloth to rub over sink. Sprinkle one tablespoon of baking soda on top of detergent. Rub the sponge over the entire sink and rinse with warm water. Be sure to dry thoroughly with a soft cloth. Professional stone cleaners, which have the safe combination of ingredients, can be purchased from most hardware stores.
Periodically hand-polish your marble or onyx sink with a soft cloth or stone polishing pad. Polishing will help keep the stone looking shiny and new and extend the life of your sink.
For some types of damage, a high quality car wax and compound can be used. After cleaning the stone, carefully wax and compound the problem area of the sink. If this does not repair the damage, call a stone repair professional for assistance.
Sandstone sinks will inevitably become dirty or covered in grime. Therefore they require routine cleaning as soil can build up and wear away the protective crust and cause erosion. Fortunately, simple cleaning solutions will do the job.
To remove cosmetic soil buildup, pour one-quarter teaspoon of stone detergent into a one quart container of warm water. Soak a rag in the solution and wipe the entire sink. Rinse with a clean, wet rag and running water.
For soap scrum removal, douse the sink with non-abrasive soap scum remover. Wipe the covered sink with a clean, wet rag and rinse with warm water.
Buff any crusty, white water deposits with a dry, super-fine steel wool to remove it. Wipe area with a clean, wet rag and buff the wet sandstone with a dry towel.
Do not store heavy or sharp objects above a sandstone sink. If they fall, or make contact with the sink, the sandstone can chip or scratch. A chipped or cracked sandstone sink can be very difficult and costly to repair or replace.